Immortals
by justcallmefaye
Summary: AUish. [As it turns out, Marceline and Bonnibel have more history than all of Ooo, and in the beginning, Marceline still had a moral code, and Bonnibel still had a heart. But a thousand years is a long time, and nothing lasts forever.]
1. Parts I, II, and III

Disclaimer: _Adventure Time_ and its characters belong to Pendleton Ward. The song "Immortals" and its lyrics belong to Fall Out Boy.

A/N: I call this "AUish" because as far as I know, none of this is actually directly contradicted by the show (not that this in any way makes it canon, haha). But it does make it plausible, so there's that. Also, I intended for this to be like eight pages of a one-shot, and it mutated, as things are wont to do in Ooo, into twenty-nine pages, much to my surprise. Since I desired it to retain its one-shot feel, I'm not splitting it into real chapters but just chunks; so, the "chapter" breaks don't really mean much, except as handy stopping points. That's also why I'm posting it all up at once because continuity is mega-rad, dude.

All that being said, I hope you enjoy the story, and reviews are also mega-rad, and lumping awesome to boot. So, like, review.

* * *

 _ **Immortals**_

 _ **i.**_

 _(they say we are what we are_

 _but we don't have to be)_

"Why isn't there any…chicken… _soup_?!"

That plaintive cry echoes throughout the dead city, ricocheting off busted cars and broken buildings, and muffling in the freshly fallen snow that clogs one of its alleys. In the alley's center, an elderly man, his skin tinting to blue, shakes his fists in futile protest at the unsympathetic leaden skies.

And nearly gets concussed by the falling can of chicken soup.

"What? I'll freeze you!" he yells, spinning around with his hands extended, crab-like, but there's nothing there—no threats, no oozing monster. Just a deep divot in the snow, shadowed blue as his skin. He lowers his hands, the fear fading from his face, and fishes out the miracle can. "Er…"

"Simon? Simon, what's going on?"

He turns around, still cradling the can, but waves arrestingly at the girl halfway out of a rusting automobile. "Marcy! Stay in the car! I've got your soup, but it's cold now—the air, not the soup, although I suppose it'd be cold anyway, being that it's in a can and all—but whatever, I mean, you're not well, and what if there's more monsters—"

His protests fall on deaf ears, as Marceline disregards his concerns and clambers through the snow to his side, even though it's up to her knees and she's decidedly not equipped to be trekking across a polar landscape. She laughs upon seeing the can, like it's the prize at the end of a long quest, but her attention is quickly caught by something in the background.

Something smiling. Something pink.

The half-demon approaches the sticky substance where it's strung across the wall. "Is this who gave you the soup?" she asks, mirroring the smile hanging in the translucent material: the happiest semicircle of a curve.

"Huh? What?" Simon bleats, and he looks vaguely at the pink goop. "What's that? You think that thing gave me this soup?" He chuckles, but it's ranging towards a cackle, and Marceline slants him a suspicious look, which swiftly swivels to fixate on the crown hanging from his belt. Simon clears his throat and tries to salvage the situation and fails rather miserably. "What? It's just a wad of sentient bubblegum."

"Simon!" she protests, glancing nervously at her magenta benefactor, whose smile has faded. "That's really mean! I think she heard you! And she probably has a name, you big jerk!"

"Eh? She? Why d'you think it's a girl? It's a blob," the man says, pointing up at the strings of gum that wander up the wall like rigging on a ship. "Quite a bit of blob, too."

"You really are a jerk," Marceline declares, laying her hands on the gum somewhat to the sides of the eyes: her best guess as to where the ears are. "And of course it's a girl. It's pink. What kinda boy would be pink? Geez."

"A bubblegum boy, that's who," Simon grouses, but there's no real fight in his words, and he exhales a long sigh. "Fine, fine. 'Princess Bubblegum' here gave me the soup, sure. Can you just eat it now? You're sick, Marcy, and I want to help you. Would you let me help you like I've always done?"

Her dark eyes narrow, not oblivious to the sarcasm riding his words, but she capitulates with a nod. "Okay. I am hungry, anyway."

He beckons, already halfway back to the dilapidated husk of the car. "Come on. It'll be warmer in here, and safer, too. Once you've eaten, we need to get out of this city. Who knows how many more slimy monsters are prowling the streets."

Marceline starts to follow him, but she hesitates, glancing back at the gum. "But what about her? We can't leave her here, Simon. Those oozy monsters might attack her next, and she can't protect herself."

"She can if she drops ballistic cans of chicken soup on their heads," he mutters, but with a note of fondness. Rather more realistically, he poses, "There's enough gum up that wall to weigh both of us down, Marcy. How do you want to go about carrying her? Or are you suggesting that we chew her up and blow the world's biggest bubble and balloon away from here?"

The half-demon child laughs. "Oh, Simon, you're so silly! Blowing a bubble, geez. You're pretty dumb for being so old. No, we…pull her down, kind of, and mush her up until she's…person-shaped. Like…like a snowman, but with gum, and a girl. A gum-girl. Yeah. We'll make a gum-girl."

One of Simon's eyebrows rockets skywards, and he cranes his neck, scanning the lattice of pink elastic roped up the wall. "Well," he says at last, "I've heard stranger ideas. What the heck. Let's give it a whirl."

Giddy, Marceline claps her hands together and turns back to the nearly-featureless face on the wall. "Did you hear that, Princess Bubblegum? You can come with us. Just…come on down here."

The smile returns, spreading wide and semicircular again, and as the child and the old man watch, the strands of pink gum shiver and contract and coalesce, creeping down the building like a vine growing in reverse; it pulls in streamers and reclaims clumps until, at long last…

Simon blinks. "It's a wad," he echoes.

Marceline crouches next to the lump, which is almost half her height and possessing all the form of a beanbag chair. "Aw, Princess, that's not right. You need to have legs! And arms! Otherwise, how're you gonna do anything?"

The small, hazy eyes are half-closed, though, as if coming this far were exhausting enough, and with a last burst of energy, a tendril extends and scrapes loopily through the snow.

The half-demon cocks her head to the side. "Sugar?" she reads, and she sends a questioning glance to her adopted parent.

Simon scratches his whiskery chin. "Makes enough sense," he muses. "Not only are simple carbohydrates the core ingredients in most metabolisms, given the fact that she's composed of gum, it might also serve some secondary, structural purpose."

Marceline's brows pinch together. "…What?"

"She can't form a body without sugar," he explains, and he sighs again, more heavily this time. "But to get sugar, we'll have to venture even further into the city."

His small companion, though, falls on her knees and hugs the pink blob. "Aw, c'mon, Simon, we have to! It'd be great to have a friend!"

He blanches. "Aren't I your friend?"

She considers this. "Well, yeah, but…you're kinda like a dad, Simon. I meant a friend who'd be another kid. And then you'd have another kid, and we'd…" She falters, her chin trembling, and tears bead up in her eyes. They slip down her cheeks in crystalline trails and drip, soundless, onto the mound of gum, which looks up at her sympathetically. "We'd be like a family."

Simon stares at her for a long time, the crown heavy on his belt. One day, he knows, the power of it will pull him beneath its gilded surface and he'll drown in its depths; one day, he won't be able to be there for Marceline, to protect or provide or simply accompany. When that day comes, he would dearly like to guarantee that she won't be alone, even if all she has left is a princess made of bubblegum.

Walking over to her through the snow, he braces an arm around her small shoulders and presses a kiss into her night-black hair. "We _are_ a family," he gently corrects her, and he empties his pack onto the ground. "Here, take Hambo," he says, passing over the teddy bear. "I think our new friend here will fit inside. That way, we can carry her to the sugar and still be able to run away if we have to."

Marceline scrubs the tears off her cheeks and grins, sharp-toothed and riotously happy, and she squeezes Hambo so hard in her arms that his seams threaten to burst. "Thanks, Simon! You're the best!"

He chuckles, a little embarrassed, but shimmies the empty pack over the pink blob and hefts the whole thing onto his shoulders. "You still need to eat your soup," he reminds her.

"Oh, right!"

* * *

It doesn't take them long to find sugar; the stuff is apparently more plentiful than chicken soup, or perhaps horrible slime monsters prefer more complex offerings. Either way, they find torn-open, paper-wrapped pounds of it spread about the shelves like snow in the first grocery they check. After exchanging a glance and a shrug, Simon sets his pack down and opens the flap while Marceline gathers handfuls of the sweet crystals and dumps them over the bubblegum blob.

Some of the grit sinks in, but most of it just spills over the top and sits there, delicious dandruff.

"Um…" Marceline bends over the bag, head tilting to one side, lips pulling to the other. "Are we supposed to do something, Princess…?"

But the bubblegum begins writhing, kneading the sugar into its own flesh, and the half-demon stumbles backwards. Simon catches her under the arms and pulls her a safe distance away, and both of them look on in wary interest as the pack begins to jostle this way and that as the gum surges about inside it. The motions are so violent, though, that the flap flops shut, and neither the man nor the child can quite summon the courage to approach closely enough to tip it open again.

At length, the shaking stills, and Marceline gets her weight back on her feet and creeps closer. There is movement again, but it is now sluggish and slow, and the half-demon reaches out and pulls aside the flap…and looks down into a face that is no longer so featureless, into eyes that are no longer so small and dark and a smile that isn't a perfect semicircle.

It's better, though. It's practically human.

Violet lashes blink across lavender eyes, and teeth as white and square as sugar cubes shine in her smile. Her skin is pale, barely pink at all, but it absorbed the majority of the sugar and so faded out; her hair retains its obnoxious shade and almost all its stickiness, too, falling in globs instead of strands around her small, round-cheeked face.

"Whoa! You're like alive and stuff!" Marceline exclaims, grinning another razor-edged smile.

The gum-girl bobs her head, and with the help of the half-demon's hand, unfolds herself from the pack, standing strong and steady on her new legs. "Bonnibel," she says in a voice that's light and sweet.

Marceline quirks a dark eyebrow. "Eh, what?"

"My name," she clarifies, and she touches a hand to her breast and bows. "I'm Bonnibel."

The other girl chortles. "Not Princess Bubblegum?"

Bonnibel tucks her chin to her chest in a posture of deep thought. "No," she says at last, "but I suppose I could be, if you want."

"Nah," Marceline dismisses, "I like Bonnibel. I'm Marceline, and this is Simon," she says, taking in her other friend with a wave.

"Yes, I heard," the gum-girl acknowledges, and she offers a bow to the old man as well. "Thank you for coming along to save me."

Simon arches a doubtful eyebrow. "We hardly saved you," he says. "You pulled yourself down off that wall without any help from us."

"Yes, but I had nowhere to go before," Bonnibel explains. "I had no reason to leave the wall for years, and no sugar to grant me form; you see, I got blown there during the final bombings." She stretches her fingers into stars and adds for emphasis, " _Splat_."

"Gross," Marceline remarks with a smirk, fangs just jutting into her lower lip.

Bonnibel nods solemnly. "Gross, indeed," she confirms, and then she smiles again, sugar-bright. "But then you two came into my alley, and spoke of friendship and family, and I…had almost forgotten about such things. I've been so lonely."

The half-demon boldly grasps one of her hands and extends her other to Simon, who completes the chain. "Well, you're not alone anymore, Bonnibel!" she declares, her smirk widening into an almost perfect semicircle of a grin.

"No," she agrees, "I'm not."

* * *

 _ **ii.**_

 _(i'll be the watcher of the eternal flame_

 _i'll be the guard dog of all your fever dreams)_

Slouched next to the campfire with her crossed arms balanced on her knees, Marceline stares through the flickering yellow flames at the sprawled figure of Simon. He's deep asleep, his crown hugged possessively to his chest, as if he fears someone will take it from him—and his fear is well founded, as Marceline has attempted exactly that over the years but has always been met with failure. Now she doesn't really try, because afterwards, Simon always seemed more enraptured by the power than before, and she doesn't want to be the one that pushes him over the edge.

She can't catch him if he falls. It's not like she can fly.

"You're doing that thing again."

The half-demon glances sidelong at Bonnibel, who's peering at her from the depths of her own sleeping bag, lavender eyes flashing orange in the firelight. "What thing?" she prompts, scratching idly at one pointed ear.

Now laughter flashes, too. "Trying to think."

"Har har," Marceline tosses back with just a smidgeon of acid. "You're hilarious, Bonni. Go back to sleep already before I bop you one."

But the gum-girl disregards that warning and sits up, smoothing out the rumples in her sleeping bag. "Really, though," she presses, "what're you thinking about? You're so intense, you look like you're gonna blow a blood vessel."

Exhaling through her nose, Marceline leans back against the half-rotten log behind her and gazes up at the stars scattered—like sugar, like snowflakes—across the velvety black expanse of sky, their light poorly hidden by the leafless branches of the surrounding forest trees. She fails to respond, although a muscle works in her jaw, pulsing like a heartbeat.

Bonnibel waits half a minute more before surrendering—but not in the way Marceline would have expected. Instead of rolling over and punching another ticket to dreamland, she wriggles out of her sleeping bag entirely and reclines at her friend's side. They're the same height, the half-demon idly observes: their arms, their legs are the same length, too. But these facts don't really surprise Marceline, and she's always secretly appreciated the unspoken explanation. After all, Bonnibel doesn't have any rules about growing up—the girl's made out of gum, for glob's sake. She could skip straight to adulthood if she wanted to, if she packed on enough sugar.

But she's always been very careful about how quickly she ages.

She's always been the same height as Marceline.

Their shoulders brush, and the half-demon sighs once more, blustery this time. "He's calling you Princess Bubblegum again."

The other girl hums, an unconcerned lilt. "It's a little creepy," she concedes, "but he's harmless. It's nothing to keep you up at night."

Marceline's lips twist in a grimace, one fang poking free. "It's not the creep-factor I'm worried about. I mean, I don't want him creeping on you, 'cause that's mega-nasty, but…" She trails off, her expression creasing further, and she pulls her legs closer to her chest, locks her arms more tightly around them; she's fairly bristling with angles, like a defensive star. "But he hasn't called you that in seven years, Bonni."

Eyes dimming, Bonnibel, too, stares across the fire.

"I think he's forgotten," the half-demon concludes in the most regretful whisper. "And not that he's forgotten that it's not your name or whatever. I think he's forgotten the last seven years altogether."

She tucks her chin in. "And he's calling you Marceline," she adds slowly as the realization occurs to her.

"Exactly," she agrees, even less than a whisper now. "He's _never_ called me by my full name. I introduced myself with it, of course, but…he never used it. I've always been Marcy." She tries to swallow, but her throat's too thick, and the knot of emotion serves to slowly strangle her.

Until Bonnibel rests a hand on her shoulder, that is; then she can breathe easier. She takes in several gulps of the cool night air, willing its chill to calm the hammering of her heart, and she shakes her head in a terribly lost motion, black hair rustling in a waist-length curtain. "What're we supposed to do, Bonni? It's the crown, I _know_ it's the lumping crown, but…I don't think I can save him from it. I mean, what am I? I'm a scrawny teenaged half-demon, not a hero. And it's taken him already. There's nothing I can do."

Pink fingers tighten in reassurance. "Perhaps not," she admits, low and gentle. "But he's not a lost cause yet."

"So, what?" Marceline rasps, half-sneering and hating the tears that burn in the corners of her eyes. "We'll sit around, twiddling our thumbs, until he becomes one?" She shoves the other girl's hand from her shoulder, not caring that such a forceful motion almost causes the threadbare fabric of her t-shirt to tear. "That won't solve anything!"

Bonnibel studies her in the shivering firelight, her expression inscrutable, her eyes dark and distant. "Not every problem has a solution," she says at length. "Some equations are broken from the beginning."

"Simon's not an _equation_ ," Marceline snarls, fangs gleaming gold, knuckles bleaching white. "He's a _person_."

A wrinkle appears in her brow. "I know that."

"Do you?" the half-demon snaps, and she unfolds her gangly limbs to stand, stiff and shaking, above her friend. "'Cause it sure as hell doesn't sound like it! It _sounds_ like you're ready to write him off, like one of your stupid experiments when they go wrong!"

Bonnibel's lips seal in a thin line, but whatever she intends to say is never heard: across the fire, Simon stirs lethargically and half-opens one swirling, ice-blue eye. "Hrm, Marcy? Is that you? Are you alright?"

Marceline slackens like a sail that's lost the wind, flapping loose against the mast of her spine. "Yeah, I'm—I'm fine," she croaks, and her voice splinters into shards. "G-Go back to sleep, old man. Glob, you're such a pain."

"Hmph! You're no cakewalk yourself, kid," he mutters, and his white-lashed eyelid drops shut again, sweeping the snowy madness out of sight.

Marceline stands there and trembles, tears sliding slickly down her pale gray cheeks, until Bonnibel breathes a soft sigh and wipes them away. The droplets soak into her sugary skin, melting shallow depressions, but the gum-girl doesn't seem to mind. "We won't leave him," she declares, fingers lingering on the slanting planes of the half-demon's face.

She snorts, but there's no humor in the sound. "He'll leave us," she points out, cracking and hollow.

"Yes, one day, he will," Bonnibel murmurs. "But we'll stay until he does. It'll be his decision."

The skin strains around Marceline's eyes and mouth, and she corrects darkly, "It'll be the crown's decision."

There is nothing Bonnibel can say to that, so she says nothing.

* * *

It takes three more months, and Simon, lost in the depravity of his magic, is no longer so harmless. A horrified Marceline has to tackle him off Bonnibel, yelling and grabbing fistfuls of his beard and his coat, and even then, she can't hold him down unaided. He's old, true, but the crown grants him terrible power, and she's just a scrawny teenaged half-demon, not a hero.

In the end, Bonnibel whacks him in the head with a stick, and even though that knocks off his crown, both girls know that doesn't make a difference anymore: the crown is in his soul, its madness buried deep where they can't dredge it out. So she hits him again and again until he's exiled to unconscious realms, but she has more trouble extricating Marceline, who's sobbing into his chest, all regret and apology and anger.

Mutilated by the magic, he has betrayed her loyalty and her love, and that knife sinks up to the hilt in her heart and twists and twists and twists.

Bonnibel manages to untangle the other girl's fingers and drag her away; Marceline is incoherent in her grief, and she lacks the clarity to walk or stand. So after a dozen paces, Bonnibel lets her friend sag against her and cry a divot into her shoulder.

Before they flee, Marceline throws the hated crown as far as she can, heaving it somewhere into the dark trees. It won't help him now—he'll always, always find it, chained as he is to its irresistible anchor—but it makes her feel a little better.

It makes her feel like she tried.

* * *

 _ **iii.**_

 _(sometimes the only pay-off for having any faith_

 _is when it's tested again and again everyday)_

Three years pass, three years without Simon—but not without snow, no; they crossed some mountains, and there was a trio of winters to contend with, but this snow melts, and it doesn't taste like insanity—three years in which Bonnibel carefully adds seemingly inconsequential amounts of sugar to her own frame, because after three more years, Marceline isn't quite as scrawny anymore. She's still a riff on the theme of angles, pointed ears and teeth and nose and sharp triangles of collar- and cheek- and hipbones, but there's a softness now that wasn't there before, even considering their meager diets, their constant travel.

Bonnibel's taken note of these changes, but she has to, she tells herself, because she has to augment her own body to match. They've grown up at the same rate, and they'll continue to do so. She's not noticing anything because she _wants_ to, oh, glob, no.

She doesn't admire Marceline's hair when it shines iridescent like a raven's wing in the moonlight. She doesn't stare when Marceline's movements are languid and lithe, smoothed by a grace that Bonnibel can't quite replicate, despite having almost exactly the same proportioned limbs. She certainly doesn't wonder what it'd be like to twine her fingers through Marceline's, and not for comfort or for support or simply not to lose one another on foggier days but _just because she can_.

She doesn't think about any of these things, ever.

Never, ever.

" _Kssh_. Earth to Bonnibel. Come in, Bonnibel. Over. _Kssh._ " And knuckles rap on her sugarcane skull.

"Ow!" the gum-girl protests, and she swats peevishly at her friend's arm. Snickering, Marceline retracts her hand and plops down beside her in her usual effortless lounge. "You're back already?"

"Yup," the half-demon replies, tilting her head back to ease the kinks from her neck; Bonnibel resolutely does _not_ trace her eyes up the slender curve of her throat. "No sign of any nasty monsters anywhere around our campsite—hooray." She raises a loose fist in a parody of triumph, and she tips her head forward again, opening one dark eye to peer at her friend. "Good thing, too, 'cause you woulda been dessert. How lost in thought were you, eh? Forget to bring a map when you wandered into that big ol' brain of yours?"

"Shut up, Marcy," Bonnibel grouses, and she sniffs importantly. "Maybe I was concocting marvelous plans about how to fix the entire world, and now you've gone and interrupted me, and everyone will suffer. Way to go."

But the other girl shrugs, an easy ripple of thin shoulders. "Well," she concedes, "I _am_ the daughter of Evil Incarnate. If I didn't ruin the world's chance for, um, a second chance, then I'd hardly be living up to the family expectations."

She squints sidelong at her friend. "Yeah…what's up with that?" she asks. "Like, how evil are you?"

"Pretty evil," Marceline quips, forked tongue flicking out from between her sharp, sharp teeth. "But seriously, I don't even know. Glob, I haven't even been in the Nightosphere since I was way young; I don't remember much, 'cept for like fire and brimstone and junk. Mom thought I'd grow up better in the human world, but I guess she wasn't expecting the Mushroom Wars. 'Course, for all I know, Dad orchestrated the whole thing. Seems kinda like his style…more souls to munch and all. Whatever, though, right? I mean, if I _am_ the harbinger of the Apocalypse or somethin', then mission accomplished 'cause, wow, did the Apocalypse happen hardcore. Go me, I guess." And she raises another fist, this one much more sarcastic, into the air and gives it a half-hearted pump.

Bonnibel absorbs this with the impartiality of a true scientist, and as such, she goes on to wonder, "Do you have any abilities? Outside of the physical characteristics, you don't seem particularly demonic."

Marceline shifts her weight, getting more comfortable against the pillows of their packs braced against the sheer cliff wall. "Who made you drink curious juice, Bon?" she asks in a lazy drawl, her eyes slipping shut, as if she intends to take a nap, conversations be damned.

The gum-girl tries not to take offense at this. "I just realized that we always talk about the present, that's all. Where we are, where we'll be going tomorrow, what's for dinner. Nothing consequential, really. Nothing about…before."

The atmosphere crystallizes, ever so slightly. _Before_ means _before Simon_ , and that just dredges up his frozen ghost. Marceline suddenly seems to have more edges than usual, but then, just as suddenly, she relaxes. "Oh, is that all?" she says, her tone determinedly light. "Well, dang, you shoulda just said. I think I've got some latent magical talent that I've never really messed with. Like I'm pretty sure I can open a portal to the Nightosphere whenever the plop I want, but really, who wants to do that? And I'm immortal, just like the old man."

Bonnibel lifts her eyebrows, impressed. "You're deathless?"

"I'm…something?" Marceline hedges, her brow furrowing, and she stares inquisitively off into the night. Storm clouds are brewing in the west; she can smell the change in the air from here, and she vaguely concedes that they'll need to set up the tent soon. "I mean, I'm aging, right? I don't know if I'll stop at some point or what. I'm only half-demon, after all. I think I'll live forever, though; it's a surety I've got in my bones. But, like…I also think I could die," she adds, more quietly. "That's in my bones, too."

"I don't want you to die," Bonnibel blurts before she can think better of it.

The other girl tips her a wink, and Bonnibel's glad the darkness hides her blush. "Aw, shucks. I knew you were sweet, but now you're just giving me cavities. Lemme just dig out my toothbrush and—"

"Shut up," she grumbles once again, and she pulls her knees in to her chest and sulks with her chin on their knobby curves.

Marceline sniggers. "Geez, I didn't know you were so sensitive. Guess you're not hard candy."

Bonnibel throws her a flinty glare. "I do have feelings, you know."

The half-demon rolls her head back again and flaps an unconcerned hand. "'Course ya do, babe. There's bound to be more than just sugar in your veins." She frowns but doesn't straighten up to ask, "Now how does _that_ work, eh? How do you function? I'm not the only mysterious person in our intrepid little duo."

"I function on the same principles as everyone else," Bonnibel says, adding conscientiously, "at least, everyone else who exists in a corporeal fashion. The only difference between us is that I'm carbohydrate-based and you're protein-based."

" _English_ , Bonni."

The gum-girl sighs. "I'm made out of sugar and you're made out of meat."

"Well, geez, you could've just said," Marceline says with hint of annoyance that smoothes into a luxurious shrug. "Whatevs. That's all I've got. I'm tappin' out."

Bonnibel stalls for a long time, trying to organize her thoughts, and they've never been so hard to file before. As of late, though, she finds that as much as she prizes her intelligence, she's liable to be receiving awards for idiocy if she remains in the unsettling grasp of this strange emotion whilst in Marceline's presence. But even with the threat of embarrassment, she can't find it within her heart to want to leave—just the opposite, in fact.

She'll do anything to stay.

Awkwardly, she clears her throat. "Marcy," she ventures, soft, "do demons…have feelings?"

" _Just_ went over this," her friend drawls, twirling one finger in a circle for emphasis.

"No, I meant like…" Her throat closes up and chokes off the words, and only with determined prying can she open the pathway again. "Like, y'know… _feelings_."

Marceline blinks up at the faraway stars and watches for a few beats as more and more of them are covered by the incoming clouds. "Like feeling-feelings? Like love and crap?"

 _Love and crap,_ Bonnibel echoes internally. _Oh, glob. What_ do _I see in this girl._ "Yes," she confirms aloud. "Like love."

"'Course," the half-demon replies, settling more deeply into her comfortable slump, lashes like crow's wings feathering on her cheeks. "I loved Simon. I loved my mom. I…think I love my dad? Ish? That one's hard to say; I don't remember the dude. I'll have to pop into the Nightosphere one of these days and have a big ol' family reunion." She shrugs again, clearly done talking.

Bonnibel's more than certain that her candy heart is going to crack in half. "And…no one else?"

Marceline furrows her brow and stares, once more, straight up at the sky. "Have I met anyone else?" she wonders, sounding genuinely confused.

The gum-girl reaches over and taps her fist into her friend's forehead, exactly as Marceline herself did when she arrived at the campsite. "Hello, you dingus! Me! What about me!"

The half-demon shifts her gaze down and across until charcoal irises meet lavender ones. "What about you?" she protests, bewildered.

Bonnibel resists the urge to throttle her, or perhaps just to burst into mortified flames. "Argh! Do you _love me_?" she all but yells. The words echo off the cliffs, mockingly hollow.

And Marceline explodes laughing. "Whoa, calm down, Bonni! Of course I love you," she says, still chortling, her arms wrapped around her ribs: "You're my best friend! Glob, what a dumb question."

A strange, curious ache sets in the back of Bonnibel's jaw, like she's eaten too much sugar—except she can never eat too much sugar, and this ache goes deeper, far deeper, right down to the molasses in her marrow. She turns aside stiffly, and it will rain soon; she can smell it too, the promise of moisture, the pressure of the surly atmosphere. They need to set up the tent. She needs to stay out of the wet, lest she start to melt.

But she gets to her feet, instead. "I'm going for a walk," she says, her voice small.

The humor hitches in her friend's smile, warping it into something closer to a frown. "Er…okay?"

Bonnibel doesn't reply, and as she wanders off into the darkness, she vows never to ask Marceline that again.

Never, ever.

* * *

It starts to rain, and Marceline curses, fumbling through their packs for coats, blankets—anything that will pass as a makeshift umbrella. "Stupid sugarbrain _knows_ she's gonna melt but goes for a freaking joyride anyway," she mutters under her breath as she irritably knots a jacket around her waist and slips a second one on properly, hiking its collar up against the rain even though her hair provides more of a barrier than the stiff material can really hope to match. "Stupid lumping sugarbrain…"

She crawls out of the tent, and the steady plunking of rain on canvas is replaced with the rather more intimate plunking of rain on her face; the droplets are fat and heavy, each one bursting like a ripe berry as they strike her skin. Marceline scowls and retreats momentarily into the tent, snatching up a well-worn baseball cap and screwing it onto her head, and the pressure of it makes her ears stick out even more, appearing almost wing-like at a glance. The cap's bill shelters her face from the deluge, though, and grants her a modicum of comfort, so she sets out again, still grumbling but no longer quite so miserable.

The cliff road is dark and wet and treacherous, and only intermittent lightning flashes illuminate its tortuous length. Once upon a time, Marceline recalls, she and Simon had flashlights, but the batteries succumbed to time and use and went to rest with everything else antebellum, and they never did manage to find replacements. Marceline retains the flashlight, though, empty and useless as it is; it's stowed in the bottom of her pack, as if it will still keep her from getting lost in the dark.

It doesn't help her now, and not just because she didn't bring it along, and she slips more than once on the slick rocks, the broken asphalt of the long-forgotten mountain pass. Rusting guardrails flare and shine in the lightning's evanescent electric glow, but there's no sign of Bonnibel, not even a trail of half-melted sugary footprints, which Marceline has been hoping she'll find. Eventually, after a quarter hour of determined trekking, the half-demon discovers that the road winds back into the mountains, and along the path of least resistance, too—or the path of greatest resistance, if you're a pessimist—because it carves a tunnel into the rock face. Its far end is a distant gray smudge, and its arched length is opaque and black.

Marceline has no time to appreciate the brief respite from the rain; her breath hisses in past her fangs, instead, when she realizes what's lying on the ground just inside the tunnel.

It's a leg, still oozing sugary blood, molasses-slow.

"Bonni?" she yells, and its first iteration is a shriek, scraping up the octaves in her throat on a train of sheer panic. She grapples for control after that and manages to shout, rather more audibly over the raging storm, "Bonni! You in here? You alive? You better freakin' answer me!"

A weak reply reaches her pricked ears, small and shrill with fear. "No! Marcy, get out of here! Go away!"

Relief washes over Marceline like a tsunami wave, and it almost topples her, too. She hangs onto her balance with grim determination, and after a wavering moment of pure nausea, she gingerly lifts the severed leg—it's surprisingly heavy, for being made of sugar—and, biting back against the acid that rises unstoppably in her throat, ventures into the tunnel.

"Don't be a total moron, dude," she says, loud and carrying, although the cheerfulness falls terribly flat. "Who d'ya think you are, the lumping gingerbread man? You can't just go around lopping off your limbs and think you'll be fine."

"Didn't you hear me?" Bonnibel's voice possesses more of an edge now, its timbre buzzing like a saw. "Get outta here!"

Marceline homes in on the sound, stumbling in her haste and the inky darkness, and she can barely distinguish the shadow of her friend from the shadow of everything else. "Here you are," she declares, and she crouches down, willing the enveloping blackness to recede so that she can investigate the gum-girl's terrible injury. "I've, er, got your leg…I'll just set it down, shall I? Like right next to whatever stump you've got left, yeah?"

Bonnibel recoils in the thick gloom, though, her shoulder blades endeavoring to burrow through the stone wall behind her. "Glob, Marcy, I don't care about my leg!"

"Now that's just blood loss talking," the half-demon dismisses, and she scootches closer again, still wielding the leg like a determined carpenter wrestling with a broken chair. "Can I borrow some of your hair, maybe? I think I can, like, glue it back on, kinda, with the gum…"

"Stop it! You don't understand! Why aren't you listening to me?" Bonnibel reaches out, and at first she twists her fingers in Marceline's jacket's sleeves, as if she wants to keep her here, but then she uses her grip to propel her friend backwards, instead. "It's still _here_! It'll attack you next—"

But Bonnibel's warning is truncated as Marceline slams into her, and that only happens because something, in fact, slammed into Marceline. The girls' foreheads knock together sharply, dizzyingly, and with a discombobulated groan, the half-demon braces her hands on the tunnel wall and tries to lever herself back up. The weight on her back, though, is so heavy, and somehow, it's getting heavier…

"What the hell?" she grunts, and this close, she can read Bonnibel's expression: utter terror. The same fear lances through her willowy frame as a voice—low and guttural and riding cold, rancid breath—purrs in her ear.

"Ahhh, you smell _good_ ," the vampire says, slow with relish, and something that feels very much like a tongue slides slickly up Marceline's neck. "Like _real_ blood, not that syrupy crap…"

The half-demon only has time to gasp, " _Oh, shit—_ " before the vampire's fangs pierce the delicate skin on her neck and delve into the mineral-rich seam of her carotid artery. Agony like no pain she has ever felt before rushes through her veins: a wildfire or chain-lightning or anything that moves too fast to be predicted or blocked. It burns, _it burns_ , and then, once her entire body is screaming itself hoarse, the pain switches direction, running against the grain of its own just-inflicted wounds as the suction starts.

She can feel like the life draining out of her, but she can't stop it.

Bonnibel tries. Not paralyzed by the vampire's poison herself, she drives her fist into the monster's head with as much power as she can manage, howling rage at him all the while. Her pummeling, though, achieves no victory, and helpless saccharine tears flood her cheeks.

Marceline's heart stops, a sudden arrest that leaves it hanging hollow behind her ribs, and it never starts again. The last thing she sees before the world fades into inescapable shadow is Bonnibel's horrified face, her eyes wide, their lavender irises washed gray in the darkness.

And then she doesn't see anything.

The vampire, swollen with blood like some disgusting, engorged spider, finally plucks his fangs from Marceline's neck and tosses her body aside with all the care and ease of a child discarding a rag doll. Another scream catches in the traffic jam in Bonnibel's throat, and she stares through the blurring screen of her tears at her friend's husk of a corpse sprawled limply on the cracked asphalt, just a shadow within a shadow.

"Mmm, delicious," the vampire says, his voice thick and lush like velvet now. "So much more satisfying than you, my candy princess. Your red was so watery, and your blood…mm, it was not very pleasing. Not nearly enough _salt_ , no." He runs his tongue, stained with Marceline's ichor, over his icicle fangs, and his eyelids flutter at the pleasure of the taste.

A thousand desires flood Bonnibel, principal amongst them the driving need to rip out the vampire's throat, but before she can rush to any foolish action, a dry laugh rasps in the air. It's a quiet sound, and she's surprised she can hear it over the continual rumble of thunder and shudder of rain. Her own heart stills in her chest when a very familiar voice reaches her ears.

"Haha, oh, wow…did you think I'd take death lying down?"

Bonnibel's gaze flickers aside, and yes, Marceline's body is stirring, awkward like a marionette that's had its strings cut and needs to learn to stand on its own. Her hair sweeps across her face in a black curtain, but the strands slip aside to reveal her eyes, gleaming red, the dark red of sullen embers in a banked fire. Her lips pull back in a terrible grin, and the once-even serration of her teeth is interrupted now by the sharper points of prominent canines.

The vampire beast still squatting in front of Bonnibel stares at her, his jaw slipping open in wordless shock. With dint of great determination, though, he manages to speak. "I didn't want to _turn_ you!" he all but squawks. "I wanted to kill you! I—I _did_ kill you!"

"I'm the daughter of Evil Incarnate," Marceline lets him know, as she let Bonnibel know, and she stretches her arms wide like she's expecting applause. "You can't _kill_ me."

She lunges then, faster than Bonnibel's eyes can follow in this gloom, and snarls her fingers in the bat-like fur rising up all over the vampire beast's body. She pivots on one foot and, with unprecedented strength, throws the monstrous form across the tunnel, where he slams into the far wall and groans pathetically.

The gum-girl stares up at her friend for a fracturing instant. "Marcy?" she whispers.

Marceline glances over her shoulder, and something in her face softens; some of the fire in her eyes dims. "This must be how Simon felt," she remarks, quiet and bitter and with half her mouth still cranked in a parody of a smirk. "Calmly accepting a curse just to protect a friend. Yeah. I think I understand now."

Her heart wrenches in her chest. "You…you came back like this…for me?" she croaks.

"Don't be an idiot, Bon," she replies, the insult curling fondly off her tongue, and her smile straightens out. "You already know I love you. Glob, you only just made me say it. So what did you expect? That I'd leave you here with this lumping freak to die? Geez." And she shakes her head. "You've got like the worst opinion of me, babe."

Her heart just writhes further. "Marcy," she echoes, plaintive and pleading—although for what, she doesn't exactly know.

"Sit tight, not that you have much choice," Marceline quips, and she jerks a thumb at the beast, who's stirring again. "I've got a vampire to slay."

The battle is hard to discern in the darkness, but Bonnibel can see that, for being new to the vampiric lifestyle—deathstyle? Unlifestyle? She'll have to work on that—Marceline manages to steal and keep the upper hand. Perhaps it's due to the fact that the other vampire seeks strength in his huge monstrous form, which might have been more of an advantage if the tunnel weren't so cramped; Marceline, by comparison, flits about easily, dodging and landing quick strikes, and Bonnibel is certain that it's not just a trick of the dark—she's certain that Marceline's flying.

The male vampire's roars suddenly cut short as the female dives in for the kill; humans might need to kill vampires with elaborate methods, all garlic and sunlight and wooden stakes in unbeating hearts, but amongst their own species, brutal violence suffices. Bonnibel closes her eyes, because even the storm-dark is not enough of a shield against the carnage, and she presses her fingers into her ears, too, so she doesn't have to hear the cold flesh tearing free of ancient bones.

She only knows it's over, then, when Marceline is gently pulling her hands down, and she blinks up at her friend. Smoldering eyes gaze back at her, level and searching, and the new vampire must feel her arms trembling beneath her grasp, as she sighs and lets go.

"Oh, Bon," she breathes sadly, "you're scared of me, aren't you."

She doesn't pose it as a question, already resigned to the answer.

"No, I'm not," Bonnibel protests, not admitting that she's more than a little disconcerted by the change. It's a lot to process, but she's a scientist by nature, and she approaches all things with as much clinical detachment as she can muster, and she scrambles for its objective comfort now. Marceline being a vampire just means there's a fresh set of variables to consider in the never-ending experiment of their lives. Nothing more, nothing less.

"My leg's torn off," she points out, as if that's a detail inconsequential enough to be forgotten. "I think the blood loss is having some ill effects on my constitution, that's all."

Marceline crouches down, her vision now augmented by the inclusion of infrared, and reviews the wound. "Yeah, it's not pretty," she remarks, her tone still a bit brittle around the edges. "I think my gum-glue idea is gonna work, though. It should keep things from getting worse, at least, while I nip back to camp and borrow a cup of a sugar, heh."

Bonnibel tugs a clump from her hair and hands the sticky wad over; the vampire accepts it without really looking and, after swiveling the severed limb so that it's lined up with the stump, she smacks it down haphazardly. "Um, there?" she ventures, tilting her head to the side without much confidence.

The other girl laughs, thin and light. "I'll seal it better while you head back to camp. Don't worry about it."

Marceline grimaces doubtfully, and she rocks back on her heels, not yet departing. The sullen embers in her eyes are shadowed by her lashes as she stares down at the ground. "I'm…not gonna end up like Simon," she whispers at length. "I know being a vampire comes with a whole ton of baggage, but I won't let the bloodlust drive me mad or anything. I won't go nuts." Her eyes flicker up. "I won't hurt you."

There's supplication in her tone. It's raw, so raw.

Brow pinching in sympathy, Bonnibel reaches out and brushes her fingertips across Marceline's cheek; the pale gray flesh is cool now, no longer suffused with the warmth of living tissue. It's more than enough to bring tears to her eyes, but she determinedly holds them at bay. "I know," she says, soft, and she taps a finger to one of the new fangs. "Besides, I have it on good assurance that I don't taste good to vampires."

"Well, we'll see about that," Marceline remarks impishly, and she sticks out her tongue, just to taunt, not to taste, but it's a fine line.

Despite the blush heating her own cheeks, Bonnibel rolls her eyes. "Glob, gross, Marcy."

The vampire chuckles and gets to her feet—or not, because she hovers above the crumbling asphalt—and this newfound ability gives her pause. After a second of deliberation, she shrugs out of her jacket, draping it over her friend, and then scoops the gum-girl effortlessly into her arms.

"Wh-What are you doing?" Bonnibel yelps, the blush returning full-force.

"Dude, I can fly," Marceline says with a shrug, and she unties the second jacket from her waist and arranges it on the other girl's legs; for a moment, then, she's just holding Bonnibel with one arm, and not apparently taxed in the slightest. "It's super radical. And, like, I can get us back to camp and to all the sugar your little candy heart desires in no time flat. Maybe it'll be the greatest thing ever, me being a vampire, eh?"

The optimism rings false, but she's trying, and hard.

After a second's hesitation, Bonnibel lowers her head to Marceline's collar, and as she shuts her eyes, she catches herself listening for a heartbeat. Her friend's chest is silent, though, and she twists her fingers in the vampire's shirt over the spot where the sound should've been. "I know it's a curse, and I know it won't be easy for you," she murmurs, throat thick, "but I'm really lumping glad you're still here."

Marceline's fingers flex. "Yeah," she agrees, "me, too."

"We'll be fine," Bonnibel adds. "We'll…we'll both be just fine."

Something like a laugh escapes the vampire as she floats out into the rain. "Oh? Is that what your science tells you? Is that a fact?" There's no real venom in her voice, though—just more bitterness.

"No," Bonnibel admits, the softest yet. "It's just faith. I believe in you. In…us."

Her lips tilt, and it might be a smile, though it's hard to tell for sure.


	2. Parts IV and V

Disclaimer: _Adventure Time_ and its characters belong to Pendleton Ward. The song "Immortals" and its lyrics belong to Fall Out Boy.

* * *

 ** _Immortals_**

 _ **iv.**_

 _(live with me forever now_

 _pull the black-out curtains down)_

Summer steals across the ravaged world, bringing warmer winds and longer days, the latter of which only yields complications for Marceline. She discovers early on—with drastic results—that vampires don't appreciate sunlight, and Bonnibel has to bodily shield her from the burning rays while she digs through her pack with blistered hands in a desperate search for appropriate articles of clothing. But layering up isn't so bad, because she doesn't really have a body temperature anymore, and like a lizard, any amount of warmth she absorbs is almost instantly dispelled. It's strange, and it takes some getting used to, but by the time they achieve the western side of the mountains, slapping on a hat and gloves in eighty-degree weather is second nature.

They could've simply begun traveling nocturnally, but Bonnibel has the worst eyesight in the dark—her fructose-filled diet isn't exactly bursting with vitamin A—and they've yet to come across a handy pair of night-vision goggles in any of the abandoned cities they encounter. They do find an unbroken pair of sunglasses, which Marceline dons with a serrated grin and a tip of her hat, and in the end, she doesn't really mind the sun.

Its indirect warmth almost makes her feel alive again.

She's aware that Bonnibel's kept a close eye on her ever since her transformation, but it's tactfully done, and Marceline knows she means well; cataloguing her strengths and weaknesses might prove useful down the road, and it would be outside of the gum-girl's nature to ignore the chance to study something. For example, it's Bonnibel who discovers that Marceline can simply subsist on the color red, not blood itself, and the vampire believes for a little while that she won't have to be a monster at all.

But the color is thin and lacking compared to the fluid, and it doesn't sustain her half as well. She hunted for food long before she turned into a bloodsucker, though, and now she's the kind of predator that other carnivores can only dream of imitating. Hunting is a breeze, and she no longer has to bother with cooking.

Still, she doesn't eat—or drink, rather—in front of Bonnibel. She just…doesn't.

Some things shouldn't be observed, even by a scientist.

But this new life, or whatever it is of Marceline's, acquires much the same rhythm as the old, and she almost forgets she's a vampire sometimes until she notices that she's hovering a few inches off the ground on absentminded instinct, or that she has a craving for strawberries that has nothing to do with flavor.

Bonnibel's still there, though, right there beside her. That hasn't changed, and that's all that really matters.

Sometimes, Marceline finds herself holding Bonnibel's hand, just to preserve the illusion of her own lost body heat in her friend's warmth.

And sometimes, she finds herself twining their fingers together, just because she can.

* * *

By autumn, they reach the coast; the ocean stretches out before them, seemingly infinite as it conquers the horizon, and the cities here seem less pillaged—still ruined by the apocalyptic might of the Mushroom Wars, but not as ransacked in the aftermath. They wander down pockmarked and desolate streets, scavenging supplies from shops, until Marceline sees one they've never found intact before: a music store.

"Oh, Bonni, we have to check this out!" she exclaims, all giddy enthusiasm, and she tugs on her friend's arm.

The gum-girl raises her eyebrows, a little surprised by this excitement. Sure, she's heard Marceline humming nonsense to herself and singing made-up songs to the moon, and sure, maybe she likes listening to her voice more than she really should, but somehow she's never actually pegged the vampire as a musician.

She allows herself to be pulled into the dark, musty, cobweb-filled interior and glances around at the veritable forest of instruments decorating the walls and littering the floor. "Do you…know how to play any of these?" she asks. Stretching out a curious finger, she plucks the string of a rotting acoustic guitar; it only makes a dull _thunk_.

"Well, no, not _know_ exactly," Marceline says. In the shade of the shop, she's busily stripping off her sun-gear until she's just left in jeans and a t-shirt, and Bonnibel rolls her eyes inwardly at the latter garment. It's such an _ugly_ shirt, like the worst thing she's ever seen, black and branded with some cartoonishly terrifying version of…she's not quite sure—zombie marshmallows, maybe, spitted for their future as S'mores?—but when the vampire found it shortly after her transformation, she was thrilled by the discovery. _Dude, this was like the best band ever,_ she confided. _And this thing's like in mint condition. Check it!_ And she tugged it on.

Of course, it fit perfectly. Fate and all that.

With the way Marceline's floating to and fro now, unable to focus on anything in the grip of her exuberant glee, Bonnibel's reminded of that day and of the fact that vampire or not, her friend is still reassuringly human. No monster would ever be this overjoyed by a t-shirt or music.

Marceline's speaking, though, and her voice drags the gum-girl back to the present with a bump.

"That's why I'm gonna try every last lumping one until I find one that fits. You don't mind, do ya, Bon? It's not like we have anywhere to go, right?" And she glances pleadingly at her friend, fingers laced together in prayer, scarlet eyes full of blood and delight.

Bonnibel shrugs. "Why not? I've still got half of that chemistry textbook left."

"Nerd," Marceline teases, lips curved in a fond smirk, and she turns eagerly to her task.

The gum-girl opens the tome and invests herself in learning, listening with only half an ear to the vampire's extremely thorough and often woefully out-of-tune exploration. She gets so lost in the wonders of thermodynamics and equilibrium that she doesn't even notice when it becomes quiet again; she reads right through to the section's end, and before she can begin learning about the properties of gases, it occurs to her that she's getting hungry, and that prompts her to look up.

Marceline's reclined cross-legged on the window sill, surrounded by discarded instruments. Her eyes are shut, loosely so as if she's only half-caught in a dream, and she cradles a red electric bass in her lap, vertically as if it were a cello with its neck extending up past her own. She isn't really playing anything, just hugging it to her chest and plucking the lowest string over and over and over again, steady as a metronome.

 _Dun. Dun. Dun._

Quietly, as if she believes she's witnessing a wizard casting a complex spell—not that she'd have half as much respect for that—Bonnibel approaches, her brow wrinkling in quizzical thought. "Marcy," she whispers, hesitant to break the almost-silence but needing to satisfy her curiosity, "what're you doing?"

The vampire doesn't open her eyes or even reply right away. She just keeps plucking that string. "I want this one," she finally replies, soft and sure.

Bonnibel considers the instrument politely, and she's picked up a thing or two, so she asks, "Are you certain? I think a regular guitar, as opposed to a bass guitar, would grant you more versatility."

"No. This one," Marceline repeats, instantaneous. "The bass…I need the bass. The vibrations of the sound…I can feel 'em in my chest, Bon." She taps one of the prongs on the top of the guitar's body, which is resting squarely on her sternum. "I haven't felt anything in my chest in a long time, not since…" She trails off, her lids rising halfway, but her ember eyes are still shadowed by the lashes. Her voice scrapes, roughshod, in her throat as she concludes, "It's like a heartbeat. It's like having a heartbeat again."

Empathy nearly overwhelms Bonnibel, and she's forced to swallow before she can speak. "Then you should definitely get that one," she agrees. "Don't forget to stock up on extra strings and all. Who knows when we'll find another place like this."

"Yeah, good idea," the vampire murmurs, still playing that lone note.

Bonnibel gazes at her for a long moment, sadness swirling in her lavender eyes. "You seem to be doing well," she ventures at last. "With the whole vampire business."

Marceline chuckles, low and dry. "Yeah, I've somehow come out on top, haven't I? I mean, sure, I have to drink blood now, but I had to eat back in the day, and a balanced diet at that—now I don't ever have to worry about getting scurvy again. Going feral, sure," she concedes, "but that's the only problem, and it has an easy solution. Just think of the positives, dude: I can fly, which is beyond mathematical; I'm super strong; I like never get tired; my teeth are even sharper; and I can heal from like any injury in no time at all. Being allergic to sunlight is hardly worth complaining about."

As Marceline mentions her healing ability, though, Bonnibel's gaze is drawn to the two holes pierced in her neck, which still gape as raw as the day they were inflicted. "What about those?" she asks, nodding at her friend's stigmata. "They've never gone away."

She reaches up gingerly, just brushing across them with her fingertips, and winces. "I don't think they're ever going to."

The gum-girl frowns at her friend's reaction. "Do they still hurt, too?"

"Nothing awful," Marceline dismisses in a show of bravado, and she lowers her hand and tilts the bass in her lap, holding it now in the more established horizontal position. "I guess that's a strike against vampirism. Oh, glob, is that three strikes? Then I'm out." She grins, but it falters, and she turns her head to stare out the window, her gaze getting lost in some middle distance.

Before she knows what she's doing, Bonnibel is shifting closer, and her own fingers extend to trace the bloodless holes. Marceline flinches away, but it's just reflex, and when she understands her friend's intentions, she relaxes against the window frame once more, tacit permission.

Bonnibel touches the pale skin beside the marks, not wishing to cause the vampire pain by poking them directly, and all she can think is that the flesh is so smooth and that she wants to touch more of it. Her fingers ache with the desire; her cheeks burn with it; but Marceline has her eyes closed again and doesn't notice. Maybe that's what gives Bonnibel the courage, or maybe she's more reckless than she ever believed, because she leans in and ever so carefully presses a kiss to the eternal wound.

Marceline stiffens beneath her touch, a more subtle reaction than her earlier one that is nevertheless infinitely more profound. A breath she habitually inhales catches in her throat.

Bonnibel still has the blood to pound in her ears, and it nearly deafens her as she draws back. "There," she whispers, barely audible to either of them. "All better."

The vampire is _blushing_ , and it must be from the blood she consumed earlier, because otherwise the reaction wouldn't be possible. But it is, it is, and heat and color she thought lost forever flow up her otherwise empty veins to settle in her cheeks.

Embarrassment is understandable, Bonnibel thinks within the haze of her own awkwardness. After all, she did just kiss her friend _on the neck_ —not a place generally associated with platonic gestures. Which it was decidedly not, but if anyone asks, she'll swear to that lie for all eternity.

Marceline at last musters a response, and it's caught between a surprised hum and a strangled grunt. Her eyes, wide and even redder than her cheeks, are fixed on the gum-girl in…it's hard to say. It might simply be shock. But then again, there might be something more than her usual banked fire burning in their depths.

"You can fix things with kisses, right?" Bonnibel remarks with a shaky laugh, several eons too belated to be a legitimate explanation.

Another indistinguishable sound escapes Marceline's throat, and she blinks a few times in an effort to regain her composure. At length, she manages to unlock her jaw and woodenly reply, "So I've heard."

The gum-girl dips her head, looks aside. "Ah, well, good. I hope it helps." She makes to move away, but Marceline lashes out, viper-quick, and snags onto her wrist. She stares down at the pale gray fingers wrapped around her own pale pink flesh, as if daring them to disappear, and when they don't, she tentatively returns her gaze to the other girl's.

Those changeable eyes, locked on hers, draw her in, and she wonders briefly if it's some sort of vampire hypnosis designed to attract prey, but she disregards that notion as ludicrous in the next second. She wanted Marceline long before she became a vampire. It's a bit moot, as thought processes go.

"You asked me once," the black-haired girl says slowly, deliberately, "if demons were capable of love."

"I did," Bonnibel confirms, her voice little more than a breath, and oh, how she can't look away.

"I'm not really a demon anymore," Marceline continues. "Bit of a downgrade, really, when it comes to my evil-factor, but…" She trails off, shakes her head. "That's way beside the point. My point is—"

"—Are vampires capable of love?" Bonnibel finishes for her, the words slipping out as gracelessly as amateur skaters on ice.

The vampire in question studies her for another timeless moment, and the setting sun somewhere outside stains everything in molten orange. And it might just be a reflection, but Bonnibel can swear that the fire in Marceline's eyes is real, and she can almost swear it's burning just for her. She shivers at the thought, despite all the heat prickling her skin.

"Yes," Marceline says, as low and rough as musical sandpaper. She tugs on her friend's wrist, pulling her closer, and lifts her other hand to the back of her neck, pulling her closer still. "The answer is decidedly yes…"

She doesn't need to breathe to live, but she needs to breathe to speak, and the air is cool and soft like twilight's last caress as it drifts across Bonnibel's lips. In the next moment, Bonnibel discovers that her lips are cool and soft, too, and that she tastes like the reddest autumn leaves and wood smoke and the promise of winter's edge, something cold and dangerous and utterly thrilling lurking just a whisper out of sight. Sensations ride down her spine on an express train to the bottom of her belly, where they curl and twist and conspire to sap all the strength from her legs.

She stumbles forward, catching one hand heavily on the window sill and blindly planting the other on the wall beside Marceline's head, and accidentally crushes their mouths together. The vampire makes a small sound, but whether that's in protest or pleasure, Bonnibel can't discern. But she does feel her grin a second later, and there's a rasp of fangs against her lower lip.

"M-Marceline," she gasps, a shuddering little breath.

"Yeah?" the vampire prompts languidly between searing kisses.

For the first time in her life, Bonnibel gives up on thinking, and she tangles her fingers in the collar of that ugly t-shirt, even though it's no longer the worst thing she's ever seen. Maybe it's the best. Maybe she'll never be able to see it again without swooning a little inside. "Just do that again." She means to make it a command, but it comes out rather closer to a plea.

The fire fairly dances in Marceline's eyes, and she obligingly scrapes her teeth across once more.

* * *

 _ **v.**_

 _(i'm bad behavior_

 _but i do it in the best way)_

Time passes.

So much time.

Centuries rise and ebb like tides in the sea of the gods, pulling the spinning, half-destroyed world along their undulating sine-wave path to infinity. Marceline and Bonnibel see all of it, or all that's left of it: they climb to the peak of the highest mountain, cross the vastest sundering ocean, and even stand on the lip of utter ruin, gazing down grimly at the subtle yet shocking transition of rocky crust to molten mantle all the way down to the starkly disconcerting glimpse of the planet's sullen iron core, almost invisible behind the rising convection currents.

They find settlements occasionally, too, groups of survivors that have cobbled together rudimentary societies.

"It's like watching history come full circle," Bonnibel observes once after they've departed a village of friendly albeit seriously mutated crab-people along the waterfront. "We're nomadic hunter-gatherers. Now other people are starting to experiment with agriculture and the concept of stationary communities. Fascinating."

"Yup," Marceline lilts in absentminded agreement, floating along on her back and picking out a new melody on her bass. "Totally math."

"More like 'totally anthropology'," Bonnibel corrects, reaching up to tweak her girlfriend's elbow.

"Bah, you keep your fancy schooling," the vampire grumbles, rolling over and out of the other's grasp, though she flickers a teasing tongue and lazily opens one eye in an inverted wink. "I'll keep the sick jams."

The gum-girl shakes her head, accustomed to these barbs; they've never been sharp, anyway. "Yeah, yeah, I'm a nerd and you're a badass. Got anything new, Marcy?"

The vampire's smirk acquires a particularly wicked slant. "I'm sure even after five hundred years I can come up with something _new_ , babe," she replies, all sultry taunt, and she waggles her eyebrows in a suggestive ripple. "Wanna bet? I know you wanna bet."

Bonnibel snorts. "What makes you think I want to bet _against_ that?" she wonders rhetorically, her own lopsided grin dimpling one cheek.

"So you're willing to find out?" Marceline presses, licking a fang in a thoughtful fashion.

Her girlfriend catches onto her collar and pulls her around in mid-air, capturing her in a sudden and clumsy but far from unsatisfactory kiss. "Glob, would you just rock my world already?"

"Yes, princess," the vampire agrees, her smile edged in razor-wire.

As it happens, even after five hundred years, Marceline _can_ come up with something new.

Afterwards, as they're lying in the grass—Bonnibel half in the sun and Marceline all in the shade—the former raises a tired question. "I wonder if there's any way to accelerate social progress—you know, get things back to where they were before the Mushroom Wars."

The vampire blinks up at the lush canopy above them, her saving grace from daylight's wrath, and she snickers, still tracing her fingers in idle swirls up Bonnibel's bare arm. "Dude, is that seriously what you're thinking about at this moment? Social progress? Really?"

She smacks her hand lightly on her girlfriend's stomach. "Don't mock me, Marcy," she chides. "I wasn't thinking about that _during_ , for glob's sake. Now that my blood's back to circulating in my brain and my hearing's returned—"

"I always consider it a bonus if I can deaden one of your senses," the vampire interrupts in a fit of cocky triumph.

Bonnibel continues speaking as if Marceline hadn't. "I think it would be beneficial to the world if we established…a role model. Display a higher-ordered society that everyone else can imitate and learn from. There's still very little security, what with gangs and bandits and glob knows what else. We're only safe because you're mega-terrifying."

"Thank you," Marceline quips with a toothy grin—and with her particular pearly whites, that's saying something.

"Indeed," the gum-girl acknowledges. "But not everyone on earth can have a vampire bodyguard. So our next best alternative is structured society."

The other girl shakes her head, grass catching in the ankle-length strands of her inky hair. "So, what, Bonni?" she poses with audible humor. "You wanna save the world?"

"No, not save," Bonnibel corrects. "The world's already been lost. But fix, perhaps. Not everything, and not everywhere, but maybe some things, here. Or somewhere else. But somewhere."

Marceline wrinkles her brow and considers her girlfriend sidelong. "Who knew you were such a hero," she remarks, but the humor is gone, replaced with a curiosity that shades towards suspicion.

"Oh, plop, no," she dismisses. "I'm not a hero. I'm a scientist. I identify problems, and I provide solutions. It's not altruistic, exactly, it's…rational."

The vampire sniggers, amused once more. "Real stirring speech, babe. You might wanna work on that before you accept your Nobel prize."

Bonnibel rolls her eyes and sighs, "Oh, Marceline. As if there's Nobel prizes anymore. But I would totally win one if there were, obvi," she adds impishly.

Shrugging and disrupting Bonnibel's comfortable repose on her shoulder, Marceline remarks, "Well, I'm all for, er, saving the world. I mean, why not. So how do you wanna go about this, eh? It sounds like it's gonna be really lumping complicated."

"First we have to research," the gum-girl declares, all confidence. "We need to get back to that one library, the really ginormous one."

"Dude," Marceline protests in an elongated whine, "Oxford is like so freakin' far away…"

Bonnibel sits up, brushing grass flecks from her skin, and reaches for her shirt. "Nevertheless," she insists, and after wriggling into the garment, she leans down and plants a kiss on her girlfriend's lips. "If you take me there, I'll do to you what you just did to me."

The vampire perks up, cautiously. "That _sounds_ totally rad, babe, but does that mean I get rewarded now or in like three weeks? 'Cause, three weeks…that's a long-ass time to wait. I'll be, like, chafing by then."

Bonnibel taps one of her fangs; it makes a faint _ting_. "You need to save your energy for flying."

Marceline scowls. "You suck, man. You really, really suck. Like hardcore."

The gum-girl casts her a fond, askance look. "So tonight, when we're done traveling for the day and you don't need to fly anymore, then I'll reward you. Geez, if you would just let me finish talking…" She trails off, smiling close-lipped and not at all mysterious, and bursts out laughing when the vampire takes to the air so quickly that she nearly collides with the trees branches above them.

"What're you freakin' waiting for?" Marceline protests, yanking on her outfit for daylight travel—gloves and hat and sunglasses crammed crookedly in place. She darts out into the golden glow once she's done, gathering up the rest of Bonnibel's clothes and tossing them in her face. "Get dressed on the way! Nobody will see! C'mon! Places to go, babe, places to go!"

* * *

The library is subjected to so many cobwebs it almost looks like it has snowed indoors, and the windows, equally subjected to centuries of grime, only let a fraction of the sunlight inside. That's just as well for Marceline, and Bonnibel very carefully navigates with a glassed-in lantern, her feet kicking up thick, choking clouds of dust.

They've been to every library in the world before now, as the gum-girl's insatiable when it comes to knowledge, and they have an established routine. While Bonnibel hems herself in on all sides with teetering towers of tomes, Marceline wanders in and out, hunting for her own meals and scavenging supplies for her girlfriend's. In her free time, she floats along the stacks, sometimes perusing the volumes for her own pleasure or fetching something new for Bonnibel, but mostly she finds a comfortable perch up in the ceiling's arches and strums out song after song on her bass.

It's a symbiotic relationship. They're both remarkably independent, for being so reliant on each other.

Weeks pass, filled with long dusty days and short dusty nights, and sometimes, Bonnibel shares her new knowledge and fledgling theories with her girlfriend, who listens politely as she hugs her bass. But by and large, the gum-girl keeps her thoughts to herself, and Marceline's unbothered by that. If something truly important comes up, Bonnibel will let her know, and there's no point pushing for answers before then. She trusts Bonnibel, implicitly.

Eventually, though, the vampire observes that the genre of the books has changed. No longer are they concerned with history or philosophy or even science; now they venture into more mystical realms, flirting with the bounds of sorcery and magic, whispering promises of power and dominion.

Marceline hovers near one of the more recent stacks, nudging aside a treatise on Marxism and idly thumbing through the biography of someone named Machiavelli, who doesn't seem like the nicest sort. "What's up with all this junk, Bon?" she wonders, one fang snaking out to balance her rising eyebrow.

The gum-girl doesn't look up from the ancient, yellowed pages of her latest interest. "Mm, oh, that stuff…that's just different theories on government, really. I need to examine every alternative so that I can create the most efficient hybrid. I've been over it all, though. I think I've got a handle on what'll work best."

The vampire nods as if she really understands. "Radical, babe," she remarks, and she floats closer to her girlfriend, glancing down over one pink shoulder. "And…what's this? I mean, if you've filled up your thinking cap, then shouldn't we make tracks? Start building…whatever we're gonna build?"

"The model kingdom," Bonnibel provides with a hum and a nod. "Yes. But you can't have a kingdom without subjects."

Marceline's lips pull to one side, and she peers closer at the page—it's written in a foreign tongue, though, and no amount of scrutiny will force it to yield its secrets to her. Somehow, that makes her feel uneasy, as if Bonnibel's hiding things from her, as if she's reading different languages on nefarious purpose. She shakes her head and tries to shake the feeling with it, but it won't quite budge.

"Er, well," she begins, slow and confused, "aren't we going with the whole, _if you build it, they will come_ notion?"

"Oh, glob, that's optimistic," Bonnibel dismisses, her eyes tracing the strange script. "And mega-naïve. You can't just build a castle and expect the right people to show up."

Everything unsettled in her belly sloshes a bit more, and Marceline swallows. "The right people?" she echoes, even though she hardly wants to hear the answer.

"Yeah," the gum-girl absently confirms. "Our model kingdom should be easily imitable, so that others can construct replicas of it without needing to acquire all the knowledge that went into devising it in the first place. Everything has to go according to plan, then, and so we'll create the subjects—subjects that will perfectly match the kingdom."

The vampire half-expects those words to echo in the library's dusty air, they're so ominous. She has no idea how to respond to that, so she just hovers there, struck dumb with this swelling dread.

"I'll need more than just science to do so, at least initially," Bonnibel continues, oblivious of her girlfriend's reticence. "I think I've discovered the answer, though. Many of these books reference Stones of Power, which seem to be collected in one special book called the Enchiridion. If we find the Enchiridion, then we'll have everything we need."

With effort, Marceline pries her teeth apart. "And where's this En-ky-whatsamajigger?" she asks, and it's so, so hard to keep her usual nonchalance tacked onto her tone.

Bonnibel flips through the thin parchment pages until she reveals the inked contours of a map. She points at it, all the explanation required.

"Oh," Marceline whispers. "X marks the spot."

* * *

There isn't an X, but buried deep beneath the ruin of a temple, condemned to millennia-long sleep in the cradle of a catacomb, there is the Enchiridion.

Marceline's skin has been crawling ever since Bonnibel set them on this quest, and now that the moment is here, she just wants to vomit—an urge she hasn't had since she used to use her stomach. The book reeks of power, giving off waves of it that entice Marceline's half-demon soul to sit up like a dog and beg, because it reeks of evil, too, and so strongly that even she wants to make it her master.

Even she, daughter of Evil Incarnate, wants to submit to its thrall.

"What is this?" she asks hoarsely, one hand raised as if she expects it to shine sunlight at her.

"Technically, it's a hero's handbook," Bonnibel explains, blowing the thick coating of dust off its leather cover. "I believe it was designed as such as a safeguard. Only someone pure of heart could claim the book, so only someone pure of heart could claim the Stones."

 _And are you?_ Marceline wants to ask but doesn't dare. _Pure of heart?_

Head cocked to the side, Bonnibel studies the book for a long moment in the flickering light of their lantern, and then she reaches out with steady fingers and twists the sword emblazoned on the cover. To the vampire's surprise, the sword spins like the hands on a clock, and a compartment in the cover cracks open, revealing glittering gemstones, arranged in a circle.

Three of them are already missing.

"Oh, plop," the gum-girl laments, her brow furrowing. "That's a bit disappointing. It'll be okay, though; I shouldn't think we need quite _that_ much power. Besides, if we do," she adds, and she digs into the stone sarcophagus that held the book and withdraws something gleaming on a chain, "we have this amulet. Pretty math, eh?"

Marceline swallows, something in her instincts—her demon instincts, again, not her vampire ones—recognizing the shape of this magic. "I dunno, Bon," she whispers. "Amulets of power are…" She trails off, trying to find the words. But for all the skill she has for penning lyrics, she can't fathom a way to subvert this doom with mere diction.

"Powerful, I bet," Bonnibel finishes for her, sounding freakishly unconcerned, and she loops its golden chain around her neck without so much as a flicker of doubt.

"What're you doing?" Marceline shrieks, and she snags at the chain. "Take it off, Bonni, take it off now!"

The gum-girl recoils, batting the vampire away with one hand and pressing the amulet's pendant snug to her chest with her other. "Fudge, Marcy, what's gotten into you?"

"Do you know what this thing does?" the vampire protests, swiping at it again—ineffectually, again. Bonnibel's stronger and faster than she should be, for being a hodgepodge of sugar and gum. "Do you even _know_ what you're taking on? What if it'd blown your head off?"

The other girl eyes her with irritation and just a pinch of pity. "Except it didn't, Marceline. It's harmless."

"Harmless?" the vampire echoes, not believing that for a second, and she glares darkly at the amulet. She wants to sink her fangs into it, bite it hard and drain its poison.

Bonnibel stares at her, lavender eyes dark in the catacomb's shadows and flickering in the lantern's light, and she shuts the Enchiridion's compartment and hugs the book to her chest as well, caging it in with her arms. "What the plop's gotten into you?" she repeats, her voice hard-edged.

Marceline's jaw works soundlessly for several iterations, incredulity jostling in the queue of other emotions. Eventually, she finds it easiest just to ignore the question and pose her own. "This kingdom," she says with difficulty. "What's it gonna be like? Who's gonna be king, eh?"

"There won't be a _king_ ," Bonnibel sniffs. "It will be a monarchy, though. All simple societies start with a single sovereign leader. Lawmaking is easier that way, as is enforcement. It will also be easier for other groups to imitate the structure—they'll only need one really capable person to begin."

Marceline's shaking. _Dear glob,_ she thinks, _I'm actually_ shaking _._ "So, what, Bon? You're appointing yourself queen?"

Bonnibel looks away. "I was thinking _princess_ , actually." Her lips curl, the ghost of smile. "Princess Bubblegum, even."

"That's sick," the vampire spits, automatic and dead-certain. "Mega-sick, and _not_ in a good way."

"I don't mean it in poor taste," Bonnibel denies. "It just seems like a good title for the ruler of a candy kingdom."

"A candy—?" Marceline echoes, and she coughs up a peal of acrimonious laughter. "Blood and hellfire, Bonnibel, what're you planning to do? Bake your subjects in your own image?"

To her horror, Bonnibel simply shrugs. "More or less, yes."

"You can't do that!" the vampire shouts, the sheer volume knocking down dust from the ancient stone ceiling. "You can't make people and then—then have them do your bidding! You're not a _god_!"

"I know that," she snaps. "I also know that if you're not going to help me, then get out of my way."

"Bonni…" Marceline staggers back a step, as if those words were a physical blow. "Y-You can't be serious. Not after all I've done for you!" And she taps two fingers to her bitemarks.

She shakes her head. "I didn't ask you to do that," she says, quiet and steady and so eerily, eerily calm. "I'm grateful, obviously, for your sacrifice, but the fact remains that it was _your_ sacrifice. I don't hold with the old-fashioned notions of life-debts, so I can do what I please with the life that you saved. And what I want is to craft a kingdom. My kingdom."

With a hollow, fracturing laugh, the vampire shakes her head as well. "Oh, Bonnibel…is this really all about power? Because I thought if either of us was gonna go crazy, it was gonna be me! Because of this!" She strikes her stigmata again. "I've been _terrified_ for _centuries_ that I was gonna snap and do something horrible. But in the end, geez, it's you, Bonni! You're the one who's gone completely whack! I never thought it would be you. I mean, come on—I'm heiress of the freakin' Nightosphere and a vampire to boot, and you're _literally made of sugar_! And probably spice and everything nice and you're freakin' _pink_ and yet somehow your heart's colder than Simon's! At least he was possessed by evil magic! You're _choosing_ all of this with your eyes wide open! It's sick!"

Bonnibel's hands tighten on the Enchiridion, and it is true: there is more ice in her eyes than there ever was in the old man's. "I already told you," she says, biting off each syllable with scientific precision, "that if you don't like it, you can leave."

The dead tissue of Marceline's dead, dead heart cringes in its bony prison in her chest, and tears spring to her eyes, tears filled with burning salt that Bonnibel's have never contained. "And go where?" she demands hoarsely, even though her arms are spread in something much more like a plea.

The self-proclaimed monarch turns away. "Wherever you like. You have the entire world to choose from."

Marceline sags, every last vestige of strength drained from her body as surely as that vampire once drained her blood. She sways in the weak breeze that worms through the catacombs, as if it truly has the power to topple her. "That's it?" she whispers.

Bonnibel doesn't look back. In fact, she begins striding away, taking her amulet and her book and her light with her. "That's it."

The words echo in Marceline's ears.

They never quite fade.


	3. Parts VI, VII, and VIII

Disclaimer: _Adventure Time_ and its characters belong to Pendleton Ward. The song "Immortals" and its lyrics belong to Fall Out Boy.

* * *

 ** _Immortals_**

 _ **vi.**_

 _(i try to picture me without you but i can't)_

Centuries pass, but this time, oh, they pass so slowly.

After some deliberation—and some tears, so many tears, entire storms and rivers and oceans, and she doesn't know how she can shed them when she never drinks any water, but even so, she can't make them stop—Marceline surrenders to fate or destiny or whatever it is and retreats from the world entirely, seeking refuge in the Nightosphere.

 _Home sweet home,_ she thinks. _Nothing like fire and brimstone to warm the cockles of my unbeating heart._

The Nightosphere is chaos, unrelenting and raw, but it seems like the most benign of tumors when Marceline considers the sterile, calculating order that Bonnibel is imposing on the world above. She tries not to think of it, though—it's impossible not to, or not to think of _her_ , but at least she tries. She lives in her father's house, watches as he presides with cruelty and stark, raving madness, and recalls that absolute power corrupts absolutely and _how's that going for you, Bonnibel?_

She samples some souls, but she doesn't really like the taste. It doesn't hold a candle to blood. (It certainly doesn't hold a candle to Bonnibel.) There's plenty of red here, though; the place is madly decorated with it; and even if she used her entire eternity to drain each morsel gray, she'll still never drink it all.

She joins a ghost gang. They're petty and stupid and mean, and Marceline finds herself hoping they'll corrupt her, that this whole place will corrupt her, because maybe if she rusts and rots, maybe then she'll be able to go back to Bonnibel and look her in the eye and not _cringe_ at that cold, cold clarity she sees there.

She writes a lot of angry songs. She writes a lot of sad songs. She writes songs for _her_ , too, with words that plead and beg and forgive and condemn and forgive again, but she burns the papers where she scrawled the lyrics. Sometimes she records them just so that she can tear the cassette tapes to shreds, just so she can watch it all fall apart.

It's lonely. She forgets things, things she ought to remember.

Then her father eats her fries, and that's the last lumping straw.

* * *

The world outside the Nightosphere is foreign to her now, and she hisses in pain as the sun scalds her flesh, forcing her to retreat into the shadow of an overhanging cliff. _Oh, yes,_ she vaguely recalls, _that happens here._

This time around, she simply adapts to being nocturnal. There's no one else's comfort to consider.

She doesn't know where to look at first, so she just flies around, refamiliarizing herself with the geography. It hasn't had a chance to change, not in a meager three hundred years, but there do seem to be more cities than she remembered. Not cities like there were in antebellum ages, towering spires of metal and glass, but cities out of antiquity, castles and fortresses of stone.

Not all of them are made out of stone, though.

One of them seems to be made out of incredibly stale cake.

Marceline floats down towards it in the darkness, and with her bird's eye view, she perceives that this is the center of it all; the other castles, the other cities ring it like planets, each on their own orbiting arc, each revolving around this sun. Landing in front of the castle door, she knocks—she's not a heathen, after all.

When someone answers, she almost cracks up laughing. It's a banana. It's alive. It has a spear.

"Who dares come to Princess Bubblegum's door at this hour?" it demands gruffly, dark little eyes glaring at her.

 _Shit, I can't believe she went with that title._ But that's an inward thought only, and outwardly, she considers for a moment and then flashes her fangs. "Tell Princess Bubblegum that Marceline the Vampire Queen wants to see her ASAP."

The banana guard's eyebrows rocket skyward. "Q-Queen?" it echoes. "Oh! Oh! Your Majesty! Forgive my rudeness! I shall fetch Her Highness immediately. Come in, come in!" It backs up, bowing over and over again, until she's standing in the entrance hall, and it skedaddles across the cavernous room and waddles awkwardly up a flight of stairs at the far end. Left to her own devices, Marceline glances around. The whole place is pink, pink and made of sugar. It's disgusting, and she wrinkles her nose and hawks a contemptuous loogie on the floor. The saliva melts into the saccharine tile, and she smirks, dark and humorless.

She's only been waiting for ten seconds total when she gets bored, and she lounges on her back in mid-air and swivels her bass around, plucking out unconscious melodies as she wonders, for the first time, what the plop she's doing here. What does she really expect to happen? What does she want to happen?

She doesn't figure it out before Bonnibel arrives.

The princess pauses but once when she catches sight of the vampire, and then she glides across the hall, straightforward as ever and seemingly pinker, but that might just be the surroundings, or because she seems to have acquired quite the penchant for purple, which only accentuates her coloring.

Marceline doesn't notice much of these details, though. Her attention is fixed only on the golden crown.

"Why is it always _crowns_?" she laments under her breath, and she slings her bass onto her back again and comes to rest on the floor and nods as cordially as she can manage. "Bonnibel."

"Marceline," the princess replies in kind, and one of her eyebrows arches. "You're a queen now? Or so I'm told."

The vampire smirks, all teeth and no heart. "I didn't want you to think you could give me orders, Princess."

"You wouldn't listen in any case," Bonnibel dismisses, and she folds her arms on her chest.

Marceline hums inattentive agreement, and she can't bite this bitterness back: "Nice crown, babe. Did it come with the title?"

Lavender eyes narrow. "In a manner of speaking," she allows, ignoring the reference to Simon, to his descent into rotten madness. A pause, and then, "Did you simply come here to harangue me?"

"That depends." The vampire cracks her knuckles, glacier-slow. "Does that mean I get to rip you a new one?"

"Crude but accurate," Bonnibel concedes, and she shakes her head, her gaze falling away. She does not attempt to speak again, leaving the ball in the other girl's court.

Marceline pushes off the floor, hovering about eight inches up, and circles the monarch like a buzzard weighing the chances of dinner. "A nice Franken-nana answered the door," she snarks at length. "That's pretty jacked up, Princess—giving life to fruit. Giving life to _anything_ and then making it serve you. Pretty freaking jacked up. I s'pose I should be thankful that you didn't cross the line of calling yourself Goddess Bubblegum and making them _worship_ you, but it's a small blessing. Practically a pittance."

Bonnibel's jaw tightens, but that is all.

"I don't see your precious amulet," Marceline continues, lashing out again, her forked tongue a whip, her fangs knives.

She sighs. "I lost it, quite a while ago."

"Is that so," the vampire murmurs, and her eyes sweep back to the crown. "Seems you didn't lose the Stones of Power. You're wearing that one pretty proudly."

Bonnibel lifts an absentminded hand to caress the opalescent stone. "I retained this one, yes," she admits. "The others I distributed amongst the kingdoms."

"Mighty gifts from their benevolent ruler," Marceline sneers. "What did they do to win your favor, eh?"

Unspoken, but glaringly loud: _What could I have done to do the same?_

The princess swallows but maintains level speech. "They established orderly, fair, and just communities. Thusly they were entrusted to guard a portion of the Enchiridion's power." She pauses again, almost as long this time, but Marceline has nothing more to say, so Bonnibel picks up the thread of the conversation by herself. "Speaking of…I'm actually glad you've come."

"Oh?" the vampire challenges, but it comes out too raw to truly be a taunt.

She dips her head. "I would ask you a favor."

Marceline barks a laugh, and it's thin and full of tears. In contrast to that response, and to Bonnibel's surprise, she permits, "Ask away, Princess."

The monarch beckons the vampire to follow, and with a half-suspicious frown, Marceline floats after her. They ascend staircase after staircase until they reach the highest room in the tallest tower, where princesses are always required to live. When she realizes where they are, the vampire summons another scathing laugh, but again, it doesn't come out quite as harsh as she wants it to.

"Wow, Bonni. Don't you think it's a bit presumptuous, asking me for a favor and then showing me to your bedroom?"

The other girl just slants her a look, otherwise not deigning to rise to that. She heads to her closet, instead, and shoves some of the boxes and dresses aside. Marceline ventures over, curiosity getting the better of her, and frowns as something catches her eye.

"Hey," she says, reaching out for the sleeve of a black t-shirt. "Isn't this mine?"

"What? Oh," Bonnibel realizes, straightening from her crouch. "Yes. I…think you must've stowed it in my pack by mistake back…well, back then. Yes. Er." She stares at the garment for a long, ticking moment, and then she returns to her rummaging. "You can take it, if you want," she offers, muffled.

The black cotton is thin and almost slick between the vampire's fingers, but cotton lasts practically forever if it's not exposed to direct sunlight, and Marceline has always been careful to avoid just such a circumstance. She's also always been careful to keep her own clothes in her own pack; she and Bonnibel have never exactly had the same taste when it comes to fashion.

Marceline's throat thickens, just a sliver. "Nah, I haven't missed it." _But you've missed me,_ she adds in the astonished silence in her head. _Maybe you're not a lost cause, after all._

"Oh, well, if that's fine with you. I guess I have enough room in here to store it," Bonnibel says, still with deliberate evasion in her voice, and then there's the heavy metallic sound of a lock slipping free, of bolts sliding back. "Come on," she adds, and she steps into the thick press of the hanging dresses.

Marceline steps closer guardedly. "Dude, where're we going? Narnia?"

The princess laughs, and now Marceline's throat does swell shut—it's been so long since she heard her laugh. It's beautiful. Musical, almost, light and bubbly. Like sugar. "Glob, no. We're just going to my strongroom."

"You have a…strongroom…" The vampire trails off, her mouth slipping open as she stares. Calling this place a strongroom is an understatement—it looks like the most fortified chamber in the whole world. "What's this lumpin' place _made_ out of?" she asks, brushing fingertips across a wall.

"The hardest substance known to candykind," Bonnibel replies, and a grin flits across her face. "Jawbreakers."

Marceline whistles appreciatively and tucks her hands into her pockets. Bonnibel is standing near the plinth in the room's center, and she floats over. "What's in the box?" she wonders, nodding at it.

In response, the monarch pulls a key from around her neck and unlocks it. There's a click and a rush of steam, and when that clears, there's the Enchiridion.

Their last meeting playing sharp across her mind's eye, Marceline wills her hands to unclench. "Why're you showing me this?" she asks, low and hollow.

Bonnibel hefts the book from its resting place, her fingers tapping arrhythmically on the leather cover. "With the Stones of Power distributed, this…well, I have no reason to have it," she decides at last. "It's a handbook for heroes, and I'm not a hero."

"Neither am I," Marceline reminds her, ember eyes gleaming crimson with the blood of the creature she killed and drained earlier that night.

For a moment, the vampire swears that the princess is going to fight her on that one, but she lets it pass. "You can fly, though. I've located a place to keep it safe, a place only a true hero can reach. You'll be able to deliver it there with ease. The trials aren't as insurmountable when you're airborne and undead."

She tugs at the strap of her bass, a nervous tic of a motion. "You're not making much sense, Bonni. Geez, look around you—this place is a freakin' fortress. Why d'ya wanna _move_ it somewhere else?"

Bonnibel shrugs. "It doesn't require a pure heart or heroic courage to get at the Enchiridion here. All it takes is the key."

Marceline has to give her that. "And that's no test for a savior," she realizes. "Just a test for a really radical burglar."

"Exactly," the princess concurs. She proffers the book, heavy beyond its physical shell. "Will you take it there?"

"If you riddle me this," the vampire replies, not yet accepting the tome. "What're you expecting to happen, eh? You're setting this up so you can judge someone competent enough to save you. So what danger do you imagine you'll need to be saved _from_?"

There's a terrible weight in Bonnibel's eyes, too, even more so than that which burdens the Enchiridion.

"Would you believe me," she whispers, "if I say myself?"

The only blood in Marceline's veins is stolen and sluggish and cool, but that statement serves to make it run cold.

* * *

She takes the Enchiridion to the appointed place, skimming through the clouds over the trials below and placing it in the hands of its new guardians. She doesn't return to the Candy Kingdom afterwards, choosing instead to wander the new, somewhat more civilized countryside of Ooo.

 _("Why's it called that? Ooo? It's a lump of a name," she asked Bonnibel before departing._

 _The princess exhaled an awkward laugh and scratched the side of her head. "Er, well, when I'd first built the kingdom, everyone who came by was so impressed by it that…well, the first words out of their mouths were, 'This place is…Ooo!', so, as a joke…"_

 _"You named a country after a_ joke _?" Marceline cackled. "Dude, I knew I loved you for a reason!"_

 _That had killed the atmosphere pretty quick.)_

That's not why she doesn't return, though. She doesn't return because she couldn't save Simon from his crown—she was just a scrawny teenaged half-demon, not a hero. Now, she's a powerful eternally-eighteen vampire, but even so…

She can't save Bonnibel from her crown, either.

* * *

 _ **vii.**_

 _(i'm still comparing my past to your future_

 _it might be your wound but they're my sutures)_

All across Ooo, Marceline claims or constructs or carves out houses. She acquires dozens, in convenient places, in whimsical places, forever searching for a home that she knows is only present in the heart of a princess made of bubblegum.

She does whatever she wants, whenever she wants to do it. She even gets a terrible boyfriend who treats her awfully because sometimes, when he smiles at her, there's a hint of Bonnibel in the curve. Eventually, though, she kicks him out, because a dash of remembrance isn't worth putting up with his crap and she's nine hundred years old, for glob's sake. She's finally outgrown fairy tales.

She's not a knight, so she doesn't get the princess. That's the long and short of it. She might as well stop pretending.

(She still doesn't have a home.)

* * *

Bonnibel labors ever for stability and progress, fashioning experiments in her lab and crafting order and prosperity outside it. She champions the rule of law, the rule of justice and decency, and in Ooo before anywhere else in the world, there is a glimmer of hope for the future.

Such hope is a little forced, a little false, since she had to create the population by herself, but there has never been any hope that could survive unsupported by sheer willpower. And there has never been any progress that rests on a foundation untainted with sin.

The world doesn't work that way. And Bonnibel is shrewd enough to understand that, and cold enough to carry it out.

* * *

Princess Bubblegum has a line of suitors (because, let's be real, they're not there to court Bonnibel herself) that she never even begins to consider—she hasn't thought about dying since that vampire ripped her leg off centuries earlier, and sees no reason to provide an heir to her throne, especially in such an uncouth way. But she glances at them sometimes, the poor candy fools, and each time she does, she experiences a little pang, because Marceline's never lounging there with her razor teeth and her red eyes and her raven-wing hair, ready and willing to sweep her off her feet and take her away from all this…gravity.

Marceline's never there at all, except in the shirt she let Bonnibel keep.

In the beginning, the princess only takes it out sometimes, caressing the ancient fabric and remembering that first heady rush of Marceline's lips on hers. She presses the cotton to her face and breathes in, deeper than deep, as if there's really a scent left there after so many hundreds of years. There isn't, of course, but the memories remain, twisted and tangled in the threads, inextricable as barbed wire in her heart.

As the years drag by and her crown grows heavier, she takes it out more and more often until she starts to wear it to bed. It protects her in her sleep, wrapping her in memories of happier times, of freer days. It adheres to her skin like armor, and maybe it's more of a talisman than she thought, because the alluring whispers of the Stone of Power fall on deafer ears.

When it gets really bad, she wears it beneath her clothes in the daytime, too.

It keeps her mind sane, but it wears her heart so, so thin.

* * *

A message arrives at Marceline's treefort during late summer when the dusk lingers thick on the western horizon, the most glorious, sullen shade of gold. She lazily pokes open the window with her foot, letting the carrier bird flap inside, and when it drops the envelope in her lap, she arches a curious eyebrow.

The bird pecks at her shoulder as she turns the letter over and recognizes the seal of the Candy Kingdom. With a frown trickling across her face, she absently sinks a fang into the scarlet wax and dissolves the seal, flicking open the paper a second later.

There's not much of a message. _Come to the castle,_ it reads. _Very important._

It's not even signed, but that doesn't matter. Marceline's been reading Bonnibel's handwriting for almost a thousand years; it's not as if she can mistake it.

For a moment, she's caught at a crossroads. The flinching pressure in her hand wants to crumple the note, and the flinching pressure in her dead heart wants to preserve it behind glass and a frame.

In the end, she scowls and shoves it in a drawer and spitefully takes her time, waiting for full night to descend before nudging open the window again and following the bird's invisible path through the skies above Ooo. The countryside below is dark except for the occasional flicker and flare of firelight, but Marceline pays it little heed, her attention fixed on the growing silhouette of Bonnibel's castle, pockmarked with bursts of light like the rolling hills.

Skipping all façade of manners, the vampire floats through one of the monarch's bedroom windows, sprawled on her back with her fingers laced behind her head. She's irritated to be summoned like this—she's irritated that she still _can_ be summoned like this, that she can't possibly refuse to come when Bonnibel calls—and she is sure to let that emotion leak into her voice.

"What doth you desire, O Great and Chewy One? What could be so lumping important that you've deigned to break a century of silence?" she sneers, her eyes stubbornly, disrespectfully shut.

She opens them, though, when Bonnibel replies.

"Marceline," she says, and her own voice is small. Very small.

The vampire peers at her, her irritation ebbing in the face of vaguely annoyed confusion and more than a modicum of concern. The princess is just standing in the center of her bedchamber, looking as small as she sounds. "What?" Marceline barks, harsher than she intends, but her nerves are starting to fray.

Bonnibel winces, though it's not clear if her pain derives from Marceline's tone or something else entirely. Either way, she approaches the vampire and, to her scalding surprise, takes hold of her hand. "There's something you need to know. It would be easiest just to show you." She wavers, gnawing on her lip. "It would also be fastest if you flew us there."

The other girl stares at her for a calculating moment, and then she exhales a sigh through her nose and hefts Bonnibel into her arms, the motion as effortless as it ever was. "Point the way, Princess," she says, soft and somehow tired.

Bonnibel does, sweeping an arm out like a compass needle, and together, they venture into the night; the moonlight ripples iridescence across Marceline's hair, and Bonnibel's body leaks warmth into the vampire's cold, empty chest. Neither of them tries to breathe too deeply, because Marceline smells like everything her shirt no longer holds—the tang of metal from her bass strings, the crispness of fallen leaves, the cloying salty rasp of blood—and Bonnibel smells less like sugarcubes and more like purest syrup, something startlingly clear and only halfway sweet.

It's easy for the vampire not to breathe, but the princess has less of a choice, and she has to keep loosening her hands from their nostalgic death-grip in the other girl's tank top as the scent and the memories nearly overpower her.

Marceline doesn't need Bonnibel's indicating finger to realize they've reached their destination; she started descending towards the snow as soon as she saw the white gleaming in the summer night. She lands lightly on the edge of it, not certain if she should set the monarch down or not; as she hesitates, though, Bonnibel lowers herself and slides a pace away, seeking the return of her compromised composure.

The vampire tries not to be offended by that distancing, telling herself it doesn't matter anyway, and valiantly refocuses. "So," she remarks. "Snow in summer."

There's not really a question in her voice, but Bonnibel nevertheless provides an answer. "Yes. Simon has come to Ooo." She pauses, glancing at her former friend to determine her reaction.

Marceline just stands there, though, stands there and stares across the unnatural ice. She seems stiff, her jaw tighter and her shoulders straighter than usual, and she bows her head in something like an acknowledging nod.

Bonnibel swallows. "He calls himself Ice King now. From what my reports have gathered, he doesn't remember the past at all. Not you, not me, not himself."

The vampire digs a small divot in the snow with the toe of her boot. "Reports, huh," she murmurs, staring into the frozen blue shadow by her foot. "You're spying on him?" Before Bonnibel can defend herself, Marceline shakes her head. "No, I get it," she dismisses. "I would, too, if I were you. You have more reason to be cautious of him than anyone." Her lips pull taut, causing the points of her fangs to flash in the starlight. "What're you gonna do?"

"Nothing," Bonnibel replies, and Marceline looks at her so sharply her neck cracks. "Seriously," the princess insists. "His crown may have deranged him, but I can't imprison a man who's already imprisoned in his own head. That would just be cruel."

A spiderweb of hairline fractures spread across the vampire's countenance, giving the impression that the slightest touch will shatter her completely. "So what're you gonna do?" she echoes, as hoarse as an asthmatic in a cigar club. "Just leave him to his own devices?"

She nods. "Unless he proves himself a deadly threat, I see no reason to act. I certainly see no reason to act preemptively."

Marceline is unwilling to let this lie, though, and she picks at it masochistically. "But before…I mean, shit, Bonni, he tried to—"

"Yes, he did," the princess interrupts, some of her own ice creeping across her words. "You don't have to remind me. I haven't forgotten. But." She shifts her weight, braces her arms on her chest. "That was almost a thousand years ago. Not that there's a statute of limitations on that crime, but…well, I have guards now. And walls. I'll be safe."

The vampire looks away. "Yeah. Safer than when all you had was me."

"That's not what I—"

Marceline holds up a hand, and Bonnibel submits to that. "It's fine," she whispers. "It's true."

 _No, it's not,_ the princess nearly blurts, but she catches the words halfway up her throat and tucks them back away. Instead, she remarks, "My reports also seem to indicate that in his advanced senility, he has in fact become rather _less_ of a threat. I think, perhaps, he is truly harmless once more. Potentially annoying, but harmless. Like…like allergies."

The vampire bobs her head, over and over and over again, as if it's loose on her neck. "Okay," she breathes, and at last, she looks up, sweeping her gaze across the wind-sculpted snow drifts. "Maybe I'll drop in on him one day." Her eyes flicker to Bonnibel's, and there's a warmth in their depths that has nothing to do with bloodfire. "See if he wants to share some chicken soup."

The princess almost tears up at that, almost flings her arms around Marceline's neck and sobs every last truth into her collar. Like _I miss you_ and _I still love you_ and _I'm so damn sorry that I hurt you_ and _You're so much better than I deserve, don't you see, that's why I can't have you_. She almost says it all.

But only almost.

"I'm sure he'd like that," she declares, bright and brittle, and she sniffs—just from the cold, just from the cold. "We should be getting back, though."

Marceline nods, still so preoccupied, and gently scoops her up again.

This time, Bonnibel doesn't play at pretenses. She snarls her fingers in the shirt and tilts her face into the vampire's chest, making sure each breath is thickly infused with her scent and pretending that the wind whipping in her ears is a heartbeat.

If Marceline notices, she doesn't say a thing.

* * *

One day, a human boy comes to the Candy Kingdom, and he's noble and brave and pure of heart. Bonnibel recognizes this, much as she is initially loathe to, and she dangles the Enchiridion in front of him. He claims it like a hero, and he does Ooo proud. He'll do her proud, too, eventually—and not just because he'll do anything to make her proud, but because her heart's not quite as hard as it seems. Not anymore.

She never tells him, though, that she's always a little bit disappointed that he's not Marceline.

She really, really thought that, in the end, her hero would be Marceline.

* * *

 _ **viii.**_

 _(i am the sand in the bottom half of the hourglass)_

The thing about mortals is that they die.

Finn lives a long and rich life. His deeds are the stuff of legend, his victories guaranteed to earn him a seat of honor amongst the gods—or so the tales promise. But in the end, he succumbs to the ravages of time, that temporal storm that has never done more than brush fruitlessly at Marceline and Bonnibel, and Ooo loses its greatest hero.

They bury him as he requested, rocketing him upwards into the stars with his collection of swords and his silly, now-threadbare hat and the bones of his faithful canine companion—Jake had passed decades earlier—so that he could have one last grand adventure, sailing eternal across the cosmos.

Afterwards, Marceline burns the treefort to the ground. She can't imagine ever living there again; it hasn't been her house in decades, and it was Finn's home like it never was hers. She respects that. She lets it die with him.

Bonnibel sits with her while it burns, and they watch as it chars itself to ash, as the beams pop and split, as the fire gutters and spikes. Somewhere in the middle, when the smoke is beginning to irritate their eyes, Marceline takes up her bass and composes their friend a tribute, the kind of epic poem that exalted the heroes of old. Tears flow freely down her pale gray cheeks before she makes it through the first verse, and Bonnibel is already crying the moment she picks up the instrument, before she even strikes the opening chord.

The only thing they save from the pyre is the Enchiridion, but it wasn't really Finn's. He was just its caretaker for a while, even if it can never hope to have a better one.

When the first light of dawn sees the last wisps of smoke dancing away on the breeze, Marceline shifts her bass onto her back, her fingertips bleeding stolen blood from the long, mournful hours of quiet song. She seems unaware of that, though, and picks up the hefty book.

"Guess it's back to the temple for this," she remarks, glancing sidelong at Bonnibel to make sure.

The princess nods and scrubs the tearstains from her face. "To await its next champion."

Marceline doesn't ask what happens if there isn't one; it doesn't occur to her, and even if it had, Bonnibel gives her no time to ask, as she's reaching over and pulling on the strap of the bass. "What're you doing?" the vampire hisses, glancing swiftly towards the sunrise. "I've gotta get going, babe."

In response, Bonnibel just shrugs out of her long coat and drapes it ungracefully over the other girl's head like it's a lampshade. "I know this is terrible timing," she says, her hand coiling around the instrument's strap again, anchoring in place. "And not just because of the dawn, but because we just lost Finn, too. He did more than protect Ooo, though; he gave us common ground once more over the years, and with it, the chance to renew our friendship." She pauses, deliberating. "We're almost there. I just need to apologize."

Marceline forces her lips to smirk. "Then grovel away, Princess."

"No," Bonnibel insists, and she tugs on the bass. "I've been working on this for a long time. I'm afraid I'm not quite the wordsmith that you are," she admits ruefully, and the vampire finally permits her to take her guitar. The strings are stained with stolen ichor, and it transfers redly to the monarch's fingers as she runs them up and down the instrument's neck; she doesn't care.

"You're gonna play?" the vampire wonders, genuine surprise in her tone. "Dude, when did you learn?"

She slants her a glance that has a shade of reproach. "I've been watching you play for a thousand years," she drawls, eyebrow tilting up, "and I didn't write the melody. I borrowed it from you." She chews on her lower lip. "It seemed most fitting that way."

Marceline adjusts the other girl's coat, making certain it's shielding her from the sun. "Go ahead then," she teases, and she tugs on the gray points peeking through her hair. "I'm all ears."

A measure of weary sorrow shadows Bonnibel's eyes, though, and she does not remark on that attempt at humor. She simply begins to play, and it's a very familiar melody to Marceline, indeed. What's worse, it's a very familiar apology, reminiscent of one she received ages and ages ago.

"La da da da-da, I'm getting buried under my crown  
La da da da-da, yeah, it's pushin' me so far down  
I know I wiped the smile from your pretty gray face  
I know I lost the one thing that I just can't replace but I'm

Sorry I didn't treat you with compassion or even courtesy  
Sorry my ambition drove you so far, so far away from me  
It was jacked up, what I was doing, but it felt necessary  
I don't know if ends justify, so I'm sorry for my means

Turn's out that, I am the problem  
Yeah, I am the problem  
It's true, I'm not very perfect, am I  
I'm just your problem

And I-I-I-I am getting buried under my crown, and  
I-I-I-I am freakin' scared I'm gonna drown  
You've gotta stay this time and save me, Marcy, please  
I promise this time I won't do lump to make you leave

'Cause I know I'm just your problem  
And know what? You're still my problem  
But maybe together, we could solve 'em  
(How 'bout it now?)

Let's try to solve 'em…"

The last deep notes fade buzzing from the bass, and Bonnibel glances up at Marceline. There are fresh tears tracking down the vampire's face, silent and as resigned to this fate as the princess appears to be herself.

"You, too, huh," she croaks, her gaze dragging to the golden circle, as hateful as Simon's crown ever was. "You said we could solve it, though. Do you know how to fix it?"

The real question, unasked: _Is it already too late?_

Bonnibel runs her fingers lightly along the strings, causing quiet little shrieks. "There's always research," she provides with the smallest shrug. "It's always worth a try."

"And if it fails?"

She shrugs again, a more exaggerated and far less casual ripple of her shoulders. That's answer enough.

Marceline feels she ought to say something, even though at this point, everything's inadequate. "I'm sorry," she manages.

Bonnibel smiles, wobbly and wet. "I'm sorry, too."

* * *

Not much happens in Ooo after that. Finn lived at the end of an era, and now, a new age of stability and peace stretches out before them, long and summer-bright as it trails after the sun. Simon's madness progresses to the point where he doesn't remember desiring princesses at all, the phantom of his fiancée finally lost beneath a millennium of snow. He calms, and fades, and Marceline plays checkers with him on the weekends and always, always brings chicken soup.

It's his favorite. He re-discovers this each time, and he's always surprised that this young vampire would like to spend time with him, but she never corrects him, and she never tries to explain. She just smiles and passes him a steaming bowl and wipes her tears away as surreptitiously as possible.

Tentative and uninvited, Bonnibel drops by on Marceline's first visit, borne aloft on a descendent of Lady Rainicorn and Jake, but she doesn't intrude on their private moment. She just waits outside the ice mountain, gently buffeted by turbulence until Marceline emerges with her empty can and her checkerboard. Neither of them speaks; they just share a look, and then the vampire hugs her so tightly that she can barely breathe.

Marceline holds on for a long while, long enough that the rainicorn starts expressing his awkwardness in apologetic Korean. She pulls away, but the shadow of her touch remains, and the bond begun in Bonnibel's song solidifies and seals, becoming something real and true and unbreakable.

Almost unbreakable.

Bonnibel's research, extensive as it is, has unearthed nothing.

* * *

They fall into a rhythm then, as they've fallen into one before. While Marceline haunts the ceilings like the world's most musical ghost—at least, when she's not touring Ooo with her latest crop of songs—Bonnibel spends her time ruling, but she delegates more these days, shaping trusted lieutenants into leaders in their own right, and begins hypothesizing about the inclusion of a senate or parliament into the Candy Kingdom's constitution.

"It worked for both the Roman and British Empires," she points out with a shrug. "It would balance the power and allow for expansion."

"Aw, geez, Bon," Marceline drawls. "Now you want an _empire_?"

But she's smirking as she says it, and Bonnibel knows better than to take her seriously when her eyes glitter like that. Some of the humor is lost on her, even so, and she leans more of her weight on her elbow so she can cradle her head in that hand. It feels thick and full of lead, the crown's slow poison seeping in. She would take it off, but that only seems to make it worse; the Stone's power nags her then, haunting and peripheral, like something she can't quite remember.

The vampire sits up straighter where she's reclining in the air. "You okay?" she asks, worry humming a counterpoint to her nonchalance.

"I'm fine," the princess dismisses. "I was just disgusted by your joke, that's all. Honestly, Marcy, I want _less_ responsibility, not more. One day, I'll be nothing but a figurehead, and one day, I won't even be that."

Marceline's eyes hover anxiously on her friend's crown. "What's less than a lumping figurehead?" she says, the humor creaking and betraying her. "All they do is smile and wave and—and—and raise little dogs in freakishly large numbers."

Bonnibel narrows her eyes, furrows her forehead, concentrates _hard_. Nothing is as easy as it was before she traded away her beloved shirt for Hambo; that garment truly was a talisman, and while she hoped that their revived friendship would prove to be an equally potent charm, it's not so tangible. It doesn't armor her while she sleeps. Things slip through the cracks…

But Marceline herself can't save her, so an old t-shirt of hers, no matter how drenched it is in memories, can hope to do the same. It was a placebo, nothing more.

"I…I don't know what's less than a figurehead," she finally mutters.

The vampire's knuckles bleach as she strangles her bass; it chunners metallically in protest. "That thing you said earlier, babe? Whatever it was? I'd get on that. Like now. The sooner, the better and all. Chop chop."

Blinking, as if she needs to reorient herself, Bonnibel gives a hesitant nod. "Yeah. I'll draft a proposal today. I'll convene the other monarchs in a few days to go over it, and then I can…issue the edicts and begin the process of…appointing magistrates." She massages her forehead, an action Marceline has seen her mime far too often recently.

Slinging her guitar onto her back, she floats down to the desk and plucks the pen from her friend's limp hand. "You talk, I write. Saves time. Time's a-wastin'. Don't got no time to waste."

The princess slants her a bemused look, and while Marceline is relieved to see the clarity refreshed, Bonnibel's words are no reassurance. "What're you talking about? Despite the fact that both of us have died at least once, me from the Lich King and you from that vampire, we seem pretty indestructible. We have all the time in the world to waste."

But Marceline just thinks of Simon, who can't remember breakfast once he's finished it, and now of Bonnibel, who doesn't know what's less than a figurehead.

"There are worse fates than dying," she declares flatly. "There are worse curses than vampirism."

It would've been better if Bonnibel argued that, but she doesn't. She already understands.

* * *

 _Time, time, time,_ Marceline panics, draining the red from everything she can reach. _Simon's crown had three Stones of Power. Bonni's only has one. And she's stronger than he was. She's so strong. Plus, she's held it off this long already. She can hold it off a little longer._

And she thinks of the Enchiridion, how it kept the Stones out of corruptible hands—and maybe not corruptible like evil, but like rust, how it bites into metal and eats it and rots it and takes away all its shine.

She can't stop thinking about the book. She gave it up, twice, but she hadn't earned it either time. It didn't mean anything to hold it then. But now the stupid book is locked behind a maze of trials designed to prove its bearer worthy.

Anyone can earn the Enchiridion.

Well, anyone who is strong and brave and pure of heart.

She wonders if it still counts even if that heart forgot how to beat a thousand years before.

* * *

"Maybe it's just the price we have to pay," Bonnibel murmurs later that week, once her proposals are drafted and her councils have convened. She strokes her fingers idly through Marceline's hair where the long strands stray across her own arm, not really aware of the action. Her eyes are shut, and she's half-asleep, and the vampire bows her tightly closed lips to her friend's shoulder. It's not a kiss, but it's close. They're not what they used to be, but they're close.

At length, she prompts, "Price we have to pay…?"

"To save people," the princess clarifies, her fingers slowing, faltering. "Maybe people who aren't heroes…maybe when they try to be them, they have to sacrifice more. Simon wanted to save you, and his crown took him. You wanted to save me, and now you're a vampire. I wanted to save Ooo, and my crown's taking me. We get what we want, but…but maybe our sanity's the price. Lost in our own heads for all eternity."

"Speak for yourself," Marceline shoots back reflexively. "I'm not off my rocker and I don't plan on falling off ever. My bloodlust is quite under control, thank you very much for asking, I'm touched by your concern."

Bonnibel chuckles, little more than a humorous exhale, and her lips curl at just the corners. "Oh, Marcy," she laments, "you're such a dingus. But I guess that's why I love you."

The vampire stiffens. It's probably not true. She's probably just forgetting intervening time, like Simon forgot it. She probably thinks they're still together, that this is five centuries earlier, or even earlier still. She probably won't remember a lick of this conversation when the sun rises.

It makes Marceline want to scream.

Instead, she kisses Bonnibel's pale pink neck, right under her ear, and whispers back, "I love you, too."

* * *

In the morning, Marceline attempts the Hero's Trials in a desperate bid to claim the Enchiridion.

She fails.

But she's known for a millennium that she's not a hero.

She's also known for a millennium that she'll do whatever she has to do in a pinch, like come back from the dead as a vampire to save the life of her only friend. So she hikes a middle finger at the universe and flies over the obstacles that she couldn't defeat, and when the guardians squabble and protest, she kicks the living daylights out of them.

"I'm Marceline the Vampire Queen," she growls as she grinds the last one's face into the dust beneath the heel of her boot. "I don't play nice, and I don't play by the freakin' rules."

"But the Enchiridion…it must judge you as worthy," he protests feebly.

"It's a lumping book," she snaps with a razor-edged scowl. "What the flip does it know?"

He doesn't seem to know what to make of that. "Er…everything it contains…?"

"Shut up," she snarls, and she kicks him hard for good measure and swivels her glare to the ancient tome. "You're just a book," she repeats, as if she's trying to convince it, or trying to convince herself. "You have no right to judge me. _I_ deem _myself_ worthy, and you're just gonna have to deal with it."

The Enchiridion doesn't burst into flames or howls or anything when she lifts it from its rest; that might not indicate that it's her by right, but it is hers for the taking, and so she takes it, takes it and flies around Ooo as fast as she can. She explains to the other rulers about the threat inherent in their crowns, but none of them believe her, none of them seem to have suffered any ill effects. For a moment, she wonders if Bonnibel's delirious musings were right—if only people who aren't heroes yet try to play the role are corruptible by the Stones.

The Enchiridion _is_ known as the hero's handbook. Maybe those who forget that fact are doomed to forget everything, and maybe heroes aren't such wonderful people, after all. Maybe they're as spiteful and vindictive and possessive as anyone, because who else would lay such a trap and cast such a curse?

Marceline doesn't know if that's true or right or anything more than a flight of fancy, but she takes the Stones just as she took the book itself—by force if she has to. Nobody has to like her after this. Nobody has to like her ever again. They can all lump off in parliamentary bliss for all she cares.

Once she collects the Stones, even the three in Simon's crown that have been missing from the book from the start, she flies the completed set and the book it resides within to the edge of the world. It takes her a long time to reach the jagged cliffs, and she almost goes feral more than once from the strain she puts on herself. She manages somehow, though, and when she gets there and gazes down at the seething heart of the planet, she is convinced she's doing the right thing.

There are extremes of power that people should not be allowed to have—the Mushroom Wars proved that.

Hovering out over the planet's mortal wound, Marceline holds onto the Enchiridion until she's above the molten mantle; it swirls sluggishly miles below.

Without preamble or any fitting, final words, she lets it go.

It might splash. It might incinerate long before it strikes. She can't tell.

All she knows is that it's gone, good freaking riddance, and that this action, while pleasingly rebellious and undoubtedly beneficial to future generations, doesn't change anything for her friends. She was too late when she began this quest, and too late even before that. Taking away the Stones of Power will do nothing for Bonnibel. It's been made amply clear via the example of Simon, and via the princess's own futile research, that the corrupting effects are irreversible.

That grates against Marceline, flays her alive. She knew she was doomed before she started, and she can picture the future facing them all: lost in their own heads for all eternity. Except for her, that is—like she said, her vampirism isn't that terrible, and even when she goes feral, she can recover. It's not like how it will be for Bonnibel and Simon. It's not the same at all.

Still, she doesn't know where that leaves her.

* * *

It takes a few more decades for the sickness to set in entirely, a few decades of stumbling pauses and a love so belatedly rekindled, but even their love, which has conquered so much, can't conquer all.

Eventually, Bonnibel forgets Marceline.

It's subtle in the end. There's just a loss of recognition in the depths of those familiar lavender eyes, the suffusion of a terrible blankness that has been erasing in from the edges for too long.

The vampire clasps their hands together—hers are shaking so badly—and she brushes her lips against the monarch's forehead.

Bonnibel looks up at her, only mild curiosity in her gaze, and she reaches out to catch a teardrop on her finger. The saline melts into her sugared skin.

"Yeah, you'll wanna be careful with that," Marceline chokes out, her serrated teeth gleaming in a watery smile.

"Okay," she accepts, and her brow pinches slightly. "Why are you crying?"

She considers that for a sticking second. "I just lost the love of my life."

"That's terrible," Bonnibel murmurs, and despite the consequences, she wipes away another tear. "What happened?"

Her mouth curves, subtle and slow, and she shrugs. "She went away."

The princess's confusion deepens as she wonders, "And you can't follow her?"

Marceline thought her heart died a thousand years ago, but as it turns out, it was merely comatose all the while, because now… _now_ it dies. She nearly slips on the mess it leaves behind, but she perseveres with grim determination—she's always been able to subvert death for Bonnibel. "No," she says through the gravel in her throat. "Not where she's gone."

"Oh," she realizes, but there's no real comprehension in her eyes. Just sympathy for a stranger. "I'm so sorry."

Marceline nods halfway, chin tucked to her chest, and just looks at her, as if she hasn't memorized everything about her centuries before. She's still so stupidly pink. And she's still so stupidly beautiful.

"Take care of yourself, Bonni," she says, as lightly as she's able, "and always be nice to little girls lost and hungry in the snow."

Bonnibel looks at her politely and doesn't understand.

(Sometimes, later, she notices the photograph taped on the inside of her closet door, and she wonders who this black-haired, sharp-toothed girl is, and whether or not they are friends. She likes to think they would be, if they aren't already. And some preferences are carved in the bones, so Bonnibel discovers over and over again that she really likes rock music, and that her favorite color is red.)

* * *

Unable to summon the strength to fly with this strangled concrete filling her limbs and the riven husk of her heart, Marceline trudges out of Bonnibel's room and unloops the princess's crown from her belt. Without its Stone of Power, it's just a fragile circle of gold, and she has strength enough to snap it in half. She drops the mangled metal on the floor and adjusts the ride of her bass's strap for a snugger fit, fishing in her pocket afterwards for a piece of chalk. Deftly, she draws a magic circle on the castle wall and smears bug milk across it.

Once she speaks the incantation, the portal to the Nightosphere yawns wide, an eternal inferno plagued with chaos. It doesn't look like home, but that's because Marceline's home is behind her, draped in a violet blanket and gazing contentedly out the window at the fading autumn sun.

She slips her pack off her shoulders and roots through its meager contents. Resting underneath the disintegrating form of Hambo, there's a lock of Bonnibel's bubblegum hair; tears prick her eyes anew when she thinks that it's really more of a wad. A sentient wad, maybe, that has a name and enough love in her heart to last a thousand years.

She likes to think that it smiles at her, as it had smiled at her before: a perfect semicircle. While she knows that isn't true—it's wishful thinking at its finest—she indulges the delusion. It's not like she has long to pretend.

She'll be forgetting herself soon enough.

Raw heat blasts across her face, whipping her hair back like the tail of the darkest comet as she steps through the portal and enters the Nightosphere. Its volcanic landscape stretches out to indeterminate horizons in every direction, and she floats above the burning madness, not paying it much attention. She's seen it all before, and she'll be seeing it until the end of time.

Her vampirism never was going to drive her insane, but it wasn't the first thing to grant her eternity, either—her demonic heritage did that.

And that which giveth, taketh away.

* * *

When she arrives in a familiar craggy mountain, her father leaps to his feet, thrilled to see her. "Marceline! What brings you all the way to hell, eh?"

"Hey, Daddy," she replies, none of her usual lilt in her tone. She gestures vaguely at the amulet resting against his chest. "I'm…here to take up the family business."

"Oh, happy day!" he cheers, oblivious of her agony, and he joyfully rips his amulet from his neck. "My little monster's ready to embrace her destiny!"

Marceline hates him for that speech, but she hates other things far more, so she accepts the burden of her birthright without comment.

As she weighs the amulet in her hand, her mind wanders back to the beginning, reviewing more than ten centuries of life and desperately searching for a loophole, for all the good it will do her now. She wonders if they could've done things differently somehow, if they could've subverted this fate, if she and Bonnibel and Simon could've lived out their undying days happily and together.

But if they saved themselves, then they couldn't save the world.

And they wouldn't be heroes.

"Huh," she murmurs to herself with a cluck of her tongue. "Not bad for a sentimental old man, a brainy bubblegum girl, and a scrawny teenaged half-demon. Yeah. Not too bad at all."

Marceline smiles one last time, real and heartfelt and true, and then she slips the amulet over her head and lets the chaos carry her away.

* * *

Elsewhere, the broken, healing world spins gently towards tomorrow.

 _(we could be immortals)_


End file.
